I’ve always wondered that, too. Why would someone be proud to be an abomination?
It’s pretty obvious it isn’t about pride. Pride is something you earn by accomplishing something. There no accomplishment in copulation.
No, this is about establishing a group identity, a united class of deviants whose hubris can stand as a bulwark against criticism and a defense against normalcy. It’s a bunch of scared adolescents whistling past the cultural graveyard.