I'm afraid I'm not aware what you're stated criteria is. No wins in 7 years as a college and pro quarterback? At least Davey won the MVP Europe award one year and played some good ball at LSU. I can imagine if Brady had gone down the year that Davey was Tom's primary backup, this entire thread would have played out the same with the current Cassell defenders stepping up to bat for Davey, trying to explain away his struggles at the QB position. The rationale? Bill had picked him as the backup so he must be good.
My keyboard has never gotten damp over Todd Collins. He is and always has been a career backup with all that the title implies. I just think that it is indisputable that he has achieved more than Cassell who (again) has the thinnest resume of any QB in the history of the NFL. I would have been quite happy had the Patriots brought in any of a number of veteran quarterbacks in the spring because I do not believe the man with no victories in seven years is the answer. But time will time.
I personally do not think Belichick holds a great opinion of Cassell, but that he was taking a gamble that Brady wouldn't be hurt. Cassell's contract is cheap, and a veteran backup would have cost more, though I don't think the cost would have been a cap buster. But if Cassell continues to play as he has, with the Patriot offense generating about 16 or 17 points per game, and Belichick keeps him in the entire season, I'll admit that I'm wrong on this point.