While the situation for LGBT people has improved greatly over the past 50 years, there is still a considerable degree of homophobia in our society today. Correct me if I am wrong, but I believe straight men are the primary perpetrators of homophobia. Generally attitudes towards LGB men/trans women are a lot worse than the other way around (many countries still criminalize sex between men but not between women).

I find this attitude to be strange and self-defeating. Many straight men today complain about not being able to find a partner, but if attitudes towards LGBT people improved, more guys would feel comfortable coming out of the closet, which would reduce competition, and improve their chances of scoring. From a rational perspective, straight men should be the first in line to promote LGBT rights.

TLDR: Promoting LGBT rights is objectively good for straight males, and I consider it a basic human right.