After I read up on it, being a "pro" is a little misleading. A lot of these guys are already national champs in their own countries. For example, Alexey could get his pro card from winning the heavys if he wanted, but he wouldn't do that (atleast for now) because he can't speak english very well and subsequently wouldn't be able to get endorsement deals in the US. Plus he'd end up sitting out the next few years trying to pack on enough mass to compete with Branch, Kai and the rest.
Botthoff refused his pro card for similar reasons.