Rolfo is an excellent rider, he has been a 250cc title contender on a slow ... honda, hes put in a reasonably impressive effort on dunlop shod motogp bike, and he has yet had a chance to prove himself on competative superbike kit.
But he really needs to come up with the goods this year, because if he doesn't it'll be the end of him. I think the reason he has been able to get this ride, and others with relative ase is that he is a marketable, multi lingual italian who brings in good sponsorship money. But not even that will save him if he wastes the ten kate honda ride.
As for charpentier, i don't know much about him because i don't watch the supersport, but being the first wss double champion would suggest he should try something harder, maybe he is a bit old(or at least hes not young), or doesn't want to move up. Or perhaps there was no room for him in the superbike team alongside money bringer and the fast one.