Well, in all fairness how long have LGBT-tolerant societies been the status quo? I'm counting about 45 years in the U.S., which is a drop in the bucket in the optic of historical trends. It remains to be seen how these new laws & freedoms affect the mores and fabric of the general population in societies where they're enabled; particularly this is true for same-gender parents and how their children will develop as a result (far too novel yet to judge).
What is certain is that if the majority of the world population was uniquely attracted to same-gender partners, the population would decline through attrition until finally only baseline levels of existence would remain. There's therefore an evolutionary case for being straight or bisexual that is missing for a purely homosexual person. To be fair, there's millions of able-bodied, hetero men who can't procreate because they can't find a partner. There's also straight couples that can't bear children without surgical procedures or surrogates. But their numbers in the population are relatively marginal so that the trend towards population growth continues more or less in linear fashion. That would not be true if the opposite was the norm.
Somewhat tangential but you have to wonder why it takes endless infomercials, rallies, talking heads on TV newsmagazines, celebrity spokespeople, entertainers and anti "hate" laws in order to get 'equality' on the same playing field for gays as straights. Force-feeding it by fiat and through mass-media manipulation of gullible (white) under 35s has an artificial quality to it that suggests it's not through the will of the people but rather through the machinations of a small special interest lobby & their powerful friends in the legislature that these 'improvements' in social standing through egalitarian lawmaking actually materialized. It feels as fake as the enthusiasm on display at 'Pride' events. The other side of the coin is that if one doesn't submit to or agree with this new paradigmatic trend towards unconditional acceptance, one is at once vilified by their coworkers, neighbors, local worthies, etc. What're they afraid of?
Before the spreading of Judeo-Christianity homosexuality was not an issue in most of the ancient world and by ancient world I mean every continent. As far as I know no society ever collapsed due to homosexuality. Religious dominance, thirst for power, money, imperialistic ambitions, etc. on the other hand, have constantly been the cause of conflicts and wars throughout history.
Regardless of modern attitutes and laws homosexuality has always been there. Same-sex couples have always existed, homoparental families were also there. It is just that they were in the dark to protect themselves but just because you didn't see them up until a couple of years ago doesn't mean they were not there. Meanwhile, heterosexual couples kept making babies; no one stopped them.
It is paranoid to always come up with scenarios where homosexuality is vilified as the cause for an eventual extinction of human population when we are going towards overpopulation; not the other way round. Certainly there will always be people who will lust after the other sex and, ultimetaly, there is assisted insemination. No need to keep bringing up ficticious scenarios as some sort of justification for homophobia with all that entails.
Empathy means to understand the struggles others face. You may not experience them on your own skin, but empathy allows you to understand others and possibly help them out instead of harming them. This is another basic principle for any community to be successful. It is natural that if anybody expresses negative or hateful views about others based on prejudices and ignorance some people will call them out on that. That happened with racism, classism, etc.
Some people tend to forget that many heterosexual people don't hold hateful views towards gainst LGB people and, eother passively or actively are in support of egalitarinism.
Ignorance breeds fear and fear wants to destroy that it doesn't understand. That's why people do what they can do achieve the desired level of equality where being LGB is not the target of violence anymore.
