[NSFW]It seems to me that a lot of sterotypically masculine guys are really insecure about inserting things up their ass. Why?

Im 28 and I have just this month started playing with my ass/inserting things up there during solo play.Why didn't I try this earlier!?!Its amazing. I get the strongest/hardest orgasms with something up there.I have always identified as straight but now Im very curious and have to try sex with another man before im 30.It seems to be that a lot of men are quite insecure about this and I just wondered why? They could be missing out.