Doc should stay (and will), and all Celtics fans should rejoice when he does.
I can understand quibbling over play calls here or there (I often disagree), or his desire to run his vets into the ground / his mistrust of many of his young players, or his continuous belief in the effectiveness of the Paul Pierce Iso (I scream at my tv), but the truth is that not many coaches in this League could have done what Doc has done over the past six seasons. In fact, I don't think any coach in the League could have.
In Year 1, Doc took a number of "stars" and molded them into a championship unit. Pierce, KG, and Allen were all set in their ways and the stars of their respective franchises. Doc brought in Ubuntu, and the 2008 championship was won. It took the Heat two seasons and in-their-prime talent to win their first title. It never happened for the Fakers this season. Doc made it work in Year 1.
In Year 2, the stalwart presence of the team's D and the on-court vocal leader went down with a knee injury, but they still won an epic 7-game series against the Bulls and lasted 7 games against the eventual Eastern Conference-champion Magic.
In Year 3, Doc led the team to within six minutes of another NBA title, even after the team's starting center went down with a knee injury.
In Year 4, an unfortunate (and malicious) on-court tackle dislocated the starting PG's elbow and ended their chances of advancing, but they still swept the Knicks in the first round.
In year 5, Doc led a team whose only playoff backups were Pietrus, Dooling, and Stiemsma to within ten minutes of making another NBA Finals appearance.
In Year 6, the team has run the gamut of injuries and age-related decline, but here they are again making noise in the post-season. They may lose Friday and be out of the playoffs, but they have put up a valiant fight. They're undermanned and less talented than their opponent. They're old and tired. But, Doc gets them to keep fighting.
And, more than that, you can tell that Doc's players truly love him and believe in him. He's a father figure to many of these guys, much the way Red was back in the day. There is genuine affection between player and coach.
We should be honored as fans to have Doc as our coach. Despite all the criticism, Doc keeps his team fighting and they continue to surpass many odds.
p.s. The ONLY coach in the League I would want to replace Doc is Tom Thibodeau. That's it. He's the only one. He has the same mentality and he's already proven himself to Boston fans. If Doc retires in a few seasons, I hope it corresponds with Thibodeau's contract, so that Ainge can hire him.