I'm a regular gym-goer, muscular (although not shredded) and I consider myself to have an appealing body. But as I'm sure you know, women have a tendency to be quite stingy with physical compliments.
Gay/Bi guys, on the other hand, are much more honest and open, and they may also have better taste in the aesthetics of men. I've been on Grindr a few times just to get the admiration of men, sometimes very attractive ones: believe me, it does miracles for your ego. I wonder if some day I'll more daring and follow up with an encounter
So, if you ask me, it's absolutely normal for a straight/bi-curious man to enjoy some gay attention. Some people just won't allow themselves to do it because of the stigma that's attached to it.