[Kneel B4 Zod]

I've often wondered about this. apart from other things in this thread, some things to consider:

some of this is just a result of hanging with other gay guys. ie I run with the hipster crowd, I'll probably end up wearing white belts. I run with the gay crowd, I'll probably end up talking like they do. Similar to the way many groups of people tend to adopt the same running jokes.

it also may just be a common way of expression and attraction. Similarly, why do many lesbians cut their hair to look like men's hair? B/c they may feel more comfortable this way, and it also may serve to attract fellow lesbians.

(granted, the % of lesbians with butch haircuts is lower than the % of lisping gay guys, but I think it's a somewhat similar phenomenom)