Homosexuality is an excellent illustration of the difference between absolute morality based on the dictates of a deity and objective morality based on humanist principles.
JWs are committed to the former. If god says something is bad then that settles it. No reasons are necessary since it is assumed god knows best. It is an infantilising worldview.
Secular ethics demand reasons. Something can only be judged as bad if it can be shown to have harmful consequences.
In many instances these two ways of thinking about morality coincide. Israel didn't really need a stone tablet to know that murder, theft and adultery were not conducive to a prosperous society.
Homosexuality is a conspicuous example of where these two cultures collide. On the one hand god says unequivocally that homosexuality is sinful, but on the other there is no rational reason for that prohibition.
Increased acceptance of gay relationships in society will have an opposite effect on the Watchtower. They pride themselves on being "no part of the world".
A lot of the comments in this and other threads have been trying to prove that JW's opposition to gay relationships is harmful. Of course it is, but to a biblical literalist it makes perfect sense. They are not looking for ways to fit in with the changing values of "the world". They actually believe they are on the moral high ground on this point and they will continue to attract followers who agree.