In the beginning of course, before sexuality between men was classified together with the Mollies and gays as 'homosexuals', it was considered a manly albeit vice -- a result of hyper-machoism, if you please. But as the society merged this sexuality with those of the third sex (homosexuals), slowly, masculine gendered men either opted out or went in the background.

This is also clear from a study of vintage porn. Till about 1960s, male porn (for men) consists of masculine, macho, 'straight' regular men. This was due to the fact that the earlier association of male-male sexuality with maschismo had still not worn out. But after the 60s, as the third sex, gay community took control of the 'homosexual' space, men, or rather straight men, slowly went out of the scene.

And if you look at 'gay' porn today, even the 'masculine' ones are so clearly feminine -- out of the ordinary, freaks.