Tankies love going on and on about how intellectual and well-read they are, but in my experience they're some of the dumbest mofos I've had the misfortune of encountering (second only to fascists). Their ability to completely miss the point of a book/article/argument/literally any interaction that involves two humans exchanging knowledge leaves me flabbergasted, every time.
By way of advice, I don't think "capitalists do it too!" is a great way to excuse China's behavior. But I agree with you in the hope that as younger people gain more power, they'll eliminate these harmful homophobic policies.
Lots of young people are bigots, and remember that every old bigot was once young as well. Bigotry can very easily be transferred from generation to generation if it is deeply ingrained in societal norms and structures.