(As my grandpa used to say) Some of these guys can't win for losing.

They turn pro by using one means (usually being in great condition and have a little bit more size than the next guy....hype works too, if you're Chris Cook!). Then as they turn pro, they realize they have to put on, not just size, but usually a ton of size. And they must do it in a fairly quick fashion.
They lose the lines that brought them to the pro stage, they don't win anything substantial because they either weren't cut out for the rigors of Pro BBing or they just don't have the genetics to respond well, or they just ruin everything because the size they pack on is not good or in the right areas.