I suspect that some pilot lack the internal drive to improve their landing skills, once let loose in the plane. ANY certified GA plane can be neatly chirped on with a bit of practice. Yes, there are differing nuances to it, but ultimately, the technique (for tricycles, anyway) is the same for all. A type change is no excuse.
Or, is someone trying to argue up the need for "type training" between Piper and Cessna!