Everyone please stop blaming Glen Rivers. Even the players are blaming the coach. Sorry but out of all the major sports Basketball is the one sport that is less effected by coaching.
Coaches don't make fouls or call fouls. Coaching don't make or miss shots. Coaches don't turn the ball over. Basketball is a simple sports, we all can go outside right now and get a 5 on 5 and not have one play called for us. An NBA coache for the most part are high price babysitters.
No, Doc doesn't play the game. However, his job is to put the team in the best position to succeed: by playing the right players, by communicating with his team, by keeping the team loose, by calling timeouts at the right time, by practicing the fundamentals, etc., etc.
As many have been saying, it's in the playoffs -- when the pressure is amplified, and where little decisions make big differences -- where coaching really matters.
My biggest problem with Doc so far in the offseason (although not the only one) is that he totally reworked his rotation, without experimenting with that rotation in even one regular season game. The last ten games of the regular season should have been spent allowing the players to learn their new roles, instead of the weird five man bench units that got heavy play. Now, more than one player is pointing fingers at the coach. None of this had to happen.
(Relegating Eddie House to the bench was a terrible, terrible decision. Once it became clear that Sam was only going to be a chucker, Doc should have reverted to what had been working, rather than relying so much on "veteran experience".)