Perhaps there is no more sensitive topic --  that generates more comments on the Internet, than a discussion or article about Gay Rights or a related issue. Though most focus on Religious issues, especially Christian Dogma, it is really not about religion or Gay Rights, it is about Eugenics.

There is little rational reasoning for reactions going on back and forth for hundreds upon hundreds of comments on articles, that would simply be based on an individual's sexual activities.  There is real fear in the thoughts of many, including the annihilation of the human race.  While that premise is absurd --  the genetic information stored in all of our genes, suggest every living human is related, simply because every human on the planet is the same species, and that is Homo Sapiens.  

Anthropologists, indicate that there may have been at least many attempts at a successful Hominid.  We, some 7 billion of us, are the sole survivors of all the attempts by natural selection.  Genetics also tells us that there was a great bottleneck in the human population, that left us only about 5000 individuals in the whole world, which is near the point of extinction. 

Perhaps, deeply ingrained in our collective psyche is that lingering genetic fear of total annihilation of our species. Though, highly unlikely at this point in time, it may be that we have genetic paranoia.  Bulk of following from Wikipedia.org...

Eugenics is the "applied science or the bio-social movement which advocates the use of practices aimed at improving the genetic composition of a population", usually referring to the manipulation of human populations.^[2][3] The origins of the concept of eugenics began with certain interpretations of Mendelian inheritance, and the theories of August Weismann.^[4]

By the mid-20th century eugenics had fallen into disfavor, having become associated with Nazi Germany. This country's approach to genetics and eugenics was focused on Eugen Fischer's concept of phenogenetics^[9] and the Nazi twin study methods of Fischer and Otmar Freiherr von Verschuer. Both the public and some elements of the scientific community have associated eugenics with Nazi abuses, such as enforced "racial hygiene", human experimentation, and the extermination of "undesired" population groups. However, developments in genetic, genomic, and reproductive technologies at the end of the 20th century have raised many new questions and concerns about the meaning of eugenics and its ethical and moral status in the modern era, effectively creating a resurgence of interest in eugenics.

Today it is widely regarded as a brutal movement which inflicted massive human rights violations on millions of people.^[15] The "interventions" advocated and practiced by eugenicists involved prominently the identification and classification of individuals and their families, including the poor, mentally ill, blind, deaf, developmentally disabled, promiscuous women, homosexuals and entire racial groups — such as the Roma and Jews — as "degenerate" or "unfit"; the segregation or institutionalisation of such individuals and groups, their sterilization, euthanasia, and in the extreme case of Nazi Germany, their mass extermination.^[16]

The practices engaged in by eugenicists involving violations of privacy, attacks on reputation, violations of the right to life, to found a family, to freedom from discrimination are all today classified as violations of human rights. The practice of negative racial aspects of eugenics, after World War II, fell within the definition of the new international crime of genocide, set out in the Convention on the Prevention and Punishment of the Crime of Genocide.^[17]

Nazi Germany under Adolf Hitler was well known for eugenics programs which attempted to maintain a "pure" Aryan race through a series of programs that ran under the banner of racial hygiene. Among other activities, the Nazis performed extensive experimentation on live human beings to test their genetic theories, ranging from simple measurement of physical characteristics to the research for Otmar von Verschuer carried out by Karin Magnussen using "human material" gathered byJosef Mengele on twins and others at Auschwitz death camp.^[124] During the 1930s and 1940s, the Nazi regime forcibly sterilized hundreds of thousands of people whom they viewed as mentally and physically unfit, an estimated 400,000 between 1934 and 1937. The scale of the Nazi program prompted one American eugenics advocate to seek an expansion of their program, with one complaining that "the Germans are beating us at our own game."^[125]

After the experience of Nazi Germany, many ideas about "racial hygiene" and "unfit" members of society were publicly renounced by politicians and members of the scientific community. The Nuremberg Trials against former Nazi leaders revealed to the world many of the regime's genocidal practices and resulted in formalized policies of medical ethics and the 1950 UNESCO statement on race. Many scientific societies released their own similar "race statements" over the years, and the Universal Declaration of Human Rights, developed in response to abuses during the Second World War, was adopted by the United Nations in 1948 and affirmed, "Men and women of full age, without any limitation due to race, nationality or religion, have the right to marry and to found a family."^[165] In continuation, the 1978UNESCO declaration on race and racial prejudice states that the fundamental equality of all human beings is the ideal toward which ethics and science should converge.^[166]

Modern inquiries into the potential use of genetic engineering have led to an increased invocation of the history of eugenics in discussions of bioethics, most often as a cautionary tale. Some suggest that even non-coercive eugenics programs would be inherently unethical.^[193] This view has been challenged by such bioethicist critics as Nicholas Agar.^[194]

In modern bioethics literature, the history of eugenics presents many moral and ethical questions. Commentators have suggested the new eugenics will come from reproductive technologies that will allow parents to create "designer babies" (which biologist Lee M. Silver prominently called "reprogenetics"). This will be predominantly motivated by individual competitiveness and the desire to create the best opportunities for children, rather than an urge to improve the species as a whole, which characterized the early 20th-century forms of eugenics. Because of its less-obviously^{[neutrality is disputed]} coercive nature, lack of involvement by the state and a difference in goals, some commentators have questioned whether such activities are eugenics or something else altogether. Supporters of eugenics programs note that Francis Galton did not advocate coercion when he defined the principles of eugenics.^[195] Eugenics is, according to Galton, the proper label for bioengineering of better human beings, whether coercive or not. Critics^[who?] counter that conformity and other social and legal pressures make eugenics programs inherently coercive; an analogous argument can be used against education on the grounds of academic inflation.

An example of such individual motivations includes parents attempting to prevent homosexuality in their children,^[196] despite lack of evidence of a single genetic cause of homosexuality. The scientific consensus in America, which stems from the 1956 research of Dr.Evelyn Hooker, is that homosexuality in any case is not a disorder. Therefore, it cannot be treated as a defective trait that is justifiably screened for as part of legitimate medical practice.^[197]

Labeling persons of reproductive age, as undesirable, or excluding them from group participation, is actually practicing a form of eugenics.  Wearing a virtual label as "Do not mate, or allow to mate." makes sure that individuals DNA is not allowed to "contaminate" the gene pool of the "protected" individuals. 

Although, being truly epigenetically gay, is not genetic, it is still an adaption of a phenotype expression. Environmental stressors experienced by the mother of a gay child, causes the X familial chromosome to make an epigenetic adjustment in the subsequent male child; therefore, the mother of the gay child has transmitted coding of sexual preference.  Anthropologists, could argue that the gay child would then be a "parental" contributor, rather than tax the familial resources for collective child rearing.  Basically, in the familial survival, the gay child would not reproduce and would not be a genetic expressor in future familial models.  The more stressors, would yield more non-genetic expressors, and population pressures would drop.  A gay is the result of over population, over competition, or reduced resources -- evolutionary adaption.