Some do train legs, some don't.
It's a physique competition that allows you to cover your legs ~
It is what it is.
Me personally? I would train everything, but for this particular competition's criteria, it isn't really necessary.
At the same time, most of these guys are not bald and have to spend a lot of time on their hair, teeth and nails. Kinda gay? Depends on how you look at it. If you win a bunch of dough and get a good contract.... well ~