You answered the question you're alluding to right there. Golly, why didn't Collins and Painter play better when they knew it could mean their jobs? Probably because who the **** is Painter? haha. Irsay fired Polian because he's a drunken idiot and probably didn't see what he was doing.
The Colts seasons 2002-2014:
10-6
12-4
12-4
14-2
12-4
13-3
12-4
14-2
10-6
2-14
11-5
11-5
11-5
As for the Bucs, they had a 20-7 lead at halftime and then decided to pull a bunch of starters and almost all of them by the 4th quarter. Golly, why would they do that? Probably because they saw that the Titans were getting their asses kicked by the (surely didn't tank) 11-5 Colts, which threatened their spot at the #1 pick.
This is a business first and foremost. They don't give a **** about all the rah rah nonsense that drives a fan.