Fair enough. That means among elite coaches, Painter ranks low in NCAA Tournament success. Same thing was true of Gene. But, that doesn't make either mediocre.
Think of all the coaches wo have coached in the top conferences over the past 20 years. Then rank Painter by wins, winning percentage, NCAA appearances, NCAA wins, conference championships, All Americans, and so on. If he ranks around the 50th percentile, then he's mediocre. But, I'm sure he's easily in the upper third in all those categories and probably higher in some.
As I said before, his failure to make the FF is a glaring hole in his resume. Same was true of Gene. But that single deficiency doesn't make either mediocre.