You ask is every male crux victim gay or bi. Of course not, no more than every female crux participant is gay or bi. It's about the cross, and the pleasure derived from the experience.
Well the idea of it is to mock them, that is why we need the buggering and the cornu. So if you see the cornu entering like this (me naturally, but before circumcision)
You mock the victim of being a homosexual and that he is not a real man, and and... you get the point. Yes, I know it is a cucumber, not a cornu, not even a dildo, but you know what I think when a female before me at the shop buys a cumcumber, one, normally... Well, she uses it for the kitchen,
. As female, I would never buy a cucumber, you know what the males think of that and how they imagine you.
Okay, go back to crucifixion, the other possibility is (hey again me depicted, but after circumcision!) is that the cornu, not a cornu but a dildo, but good enough for the safe crux idea, like this
so no easy going, no erection, pain instead of joy. Then you mock them as being an homophobic asshole, not taking it like a real man. In my case it is diabetes 2, while there is no erection, so you mock him as old, ugly and unhealthy and dirty man.
So you get the point, you have to humiliate him and for that one needs a little flexibility.
For a good crucifixion, both the crucified, but also the audience needs a lot of flexibility, and the audience has also to show a lot of fantasy.
Actually it is more easy to be the crucified, to whom the guards tell every thing what he has to do and help with it, than to be in the audience, where you are essentially alone and responsible for yourself. That explains to me, why most people like to be crucified instead of having the tedious job to be in the audience.