Well I'm sorry but it's simply not a valid opinion to say that a coach is not at least a "good" coach when he led his team to a 13-0 record, including an impressive bowl win. You don't seem to be acknowledging a distinction between good and great.
Regardless of the talent level of his team, going undefeated certainly puts Frost in the "good" category. Not to mention, you seem to be forgetting (or maybe you didn't know) that UCF went 0-12 the year before Frost's arrival. 0-12! Where was all their awesome talent then?
I agree with you that Frost appears to have been overrated, based on the total lack of success he's having at Nebraska. Is he a great coach? It doesn't look that way to me right now. But you're being contrarian and going too far by saying he's not even good.