Well, given that lots of straight porn is very anal (especially I notice in America -- maybe circumcised dicks need a tighter hole??), it's not the anal part. And for many, being a top isn't gay (as long as you don't mention it and are homophobic) so I think many men recoil at the thought of being penetrated.
And do you think this is tied with the whole fucked = effeminate thing? Was your goal in creating grero to remove that effeminate/submissive connotation? Or like create a new concept where that association never existed? I realize that you do get gay guys that are, by nature, really submissive. They will never be a top, and that's fine. What gets me is that there is this inherent contradiction with looking down (haha) on a bottom. Especially with one that chooses to bottom and isn't necessarily passive or submissive at all. And the contradiction is that the people giving the kinda sneery, superior looks are often those really,
really masculine guys. They ARE their masculinity. They will never bend over, they ooze testosterone in a musky halo. But if you're confident in your masculinity, and confidence often goes with masculinity, why is that masculinity lessened by being a bottom? If its a choice how are you less of a man? Why is being with a guy
any kind of effeminate? Because one has to be the "woman" in the relationship?
This is a complicated issue though. It ties in with so many other things. Like how society sees women and gender role stereotypes and the heteronormative hegemony. And patriarchy also wiggles in there I suppose if only because patriarchy and heteronormativity seem so linked.