IF we blow it up this summer (not just trade veterans for veterans), I could also imagine a new coach having as bad a W-L record, or maybe worse. But you're equating that with a failure of the coach, and I'm not. I expect a coach to utilize our players wisely, get all the parts working together, and get the guys playing hard so that it's fun to watch. If he does that with a very weak roster and we continue losing games, then I say: three cheers for the coach! He did all he could, our youngsters improved a lot, we saw some exciting games, and we get another shot at the lottery.
But, unless we trade Artest, Bibby and SAR for utterly worthless enders, and get no youngsters out of the deal, I doubt that we'll lose more games. Last year our "team" was much worse than the sum of its players. A bunch of scrubs who were motivated and working together would do at least as well, as some truly horrible rosters showed us last season.
I'll be the first to blame a coach for failure to execute the coach's job description, but I'm not about to blame a coach for shortcomings of the GM and owners, or for the existence of a natural team lifecycle.