How come so many of the top heavyweights these days have no inside game?

I don't know if this is just me being stupid but there seems to be so many top heavyweights that just do not know how to fight inside, even some of the shorter guys don't seem that comfortable, people like Eddie Chambers and David Haye despite there shorter size don't really seem to like to be inside. Wlad and Vitali have no real inside game but their size makes up for that and there's really no need to develop the ability to fight inside for them, tomasz adamek doesn't seem the greatest inside fighter and he likes to use the ring and move, Alexander Povetkin looks uncomfortable on the inside whenever I see him. The only 2 Heavyweights I know that like to fight inside really are Chris Arreola and Derek Chisora Is this just me being cynical or do you guys agree??