There is the same evidence for most programs, until there isn't. Outside of the Blue bloods most teams don't have piles of final fours and championships. Baylor for instance was coached by the same coach for 17 years before they broke through, and had much worse performances than Painter leading up to that point. Same could be said about Virginia.
Without the name of a Blue Blood getting a "hall of fame" coach isn't very easy. Usually you can get someone who can recruit, someone who can coach X/O, someone who can develop players, or someone who is just clutch at coaching down the stretch. Very rarely do you get someone that can do it all, and if you do one of the top name programs will steal them pretty quickly.
Painter is elite at X/O, great at player development, good at recruiting, and bad at clutch coaching down the stretch. He has shown he can improve, contrary to this board's opinion, as is seen in his improvement in his recruiting.
Best way to overcome his clutchness issues is to keep going into the tourney as a top seed. Eventually we will break through......