Brooks was too stubborn to bench Perkins in the Finals when it was clear he was woefully ineffective against Miami. He's gotten better with that (see: benching Sefolosha and then Butler in the playoffs), but I'm not entirely accepting of the idea that he would readily change his iso-heavy offense. That's a fundamental shift in his game plan; benching Sefolosha/Butler was just shuffling around replaceable role players, which a coach SHOULD be willing to do when necessary.
And again, it's simply illogical to jettison Westbrook over the coach. You don't trade away a top 10 player to retain a coach who hasn't won anything significant yet. Particularly when that top 10 player isn't even to blame for the team's shortcomings the past two seasons -- that is, unless you want to hold getting injured by Patrick Beverley against Westbrook.
Westbrook was, BY FAR, the team's best player throughout the playoffs this season and that's not because he wasn't letting Durant shine. Durant had his worst playoffs since his first appearance, probably because he was burnt out from carrying the team during Westbrook's absences in the regular season since - *gasp* - that's the type of offense Brooks runs.
OKC went down in 2013 because Westbrook was hurt. They went down in 2014 arguably because Ibaka was hurt and because their role players grew less effective as the playoffs went on. Even in 2012, you can't put the Finals loss squarely on Westbrook, since it was more of a team-wide issue: inexperience. Brooks didn't adjust, Harden was a no-show, and KD simply wasn't good enough yet to outplay LeBron, though he most certainly held his own. Westbrook had baffling gaffes, but it'd be beyond disingenuous to argue that his foul against Chalmers in Game 4 was to blame for OKC losing the Finals.