I've been supporting Haley since he arrived, but I think it's time he goes.  Here are some reasons I believe this:

1.  Going for it on 4th down.  

We all know that Haley likes to go for it on 4th down, even in field goal range.  There are reasons why this is sometimes a good move, but I don't think Haley ever thinks about why it might be a bad move.  In a 10-7 playoff game against the Baltimore Ravens you take what points you can get.  I understand that a FG was not a sure thing, but that playcall was a sure non-1st down.  I understand that Haley doesn't call the plays, but I would bet good money he had something to do with that call and if not you kick the FG anyways and tie it up.  

2. Immaturity

We are a young team with an immature Head Coach.  That is a very bad combination.  I think the players all like Haley, I do to as a person, but when the game is on the line I don't want Haley coaching my team.  He is too reactive and overthinks himself.  A coach who is not swayed by emotion would be ideal.  I believe his immaturity is half the reason Weis left and probably conflicted with Weis' playcalling as well. 

3. Offensive philosophy

Haley's offensive philosophy might be fine with Kurt Warner at QB, but with Cassel we need to run the ball and use the TE more.  At halftime we were down 10-7 and looking good, after the half we stop using Charles (again) and try to start airing it out against a man-to-man D with blitzers lining up for their shots on Cassel.  Cassel can't handle that (which is another problem imo) and Haley/Weis don't understand that or have convinced themselves otherwise.  We need a coach with a run first mentality and build your passing game around that.  Haley isn't that guy.

4. Toughness

I think Haley is all bark, no bite.  I hate to paraphrase 2.7, but the guy never played football.  He's all x's and o's with absolutely no toughness other than a possible need for anger management.  This is something I've become convinced he can never fix and is quite possible the reason we are going to get housed every time we play a tough team.  

Who is a better coach?  I don't know a specific one, but I believe that we are rebuilding and we need to get one now rather than later.  It's much easier to get a new coach in here when you have so many young players with so much to learn.  Don't let them learn their coaches bad habits now, get rid of him and bring in a tough, level-headed, defensive minded head coach.  Now that I think about it I think Romeo Crennel would be a good head coach for this team.  Sure he failed his first time, but that was in Cleveland.  Many a coach has failed in Cleveland.  Bellechick anyone?  I'm sure he's learned from the past and the players, especially this young D, would play hard for him.  

Ugh, you know it's bad when I'm calling for Romeo Crennel to be our head coach, but I honestly think he would be a massive upgrade over Haley.