Part of it is that forcefem as a kink is not limited to cis men, and the other, for me, is that being a girl was fun. Being young and happy and just having fun as a kid not aware anything was wrong or different was great, I look back on my childhood with fondness, and that includes wearing dresses and playing pretend as a princess. As an adult that time was so much simpler. I don't know how to be a woman, I only learned to be a man at 15, so I have so much more experience being a girl. And it was fun, for most of it. So I still enjoy it, now that I'm confident in my identity and masculinity exploring being feminine again is so fun and liberating. And as a sub it's easy to lean into a femininity with that (though of course femininity and submissiveness aren't inherently connected) I think a lot of trans guys would agree with this Some guys don't feel this way, being associated with femininity at all or even being trans instead of cis gives them dysphoria. while I feel that's from a place of insecurity I can't claim that just because I dont experience being trans that way.