Here is what you really need to know. Last year they bumped a 1 loss OhSt over a 2 loss conference champion PSU. The same logic was used this year to put Bama in over OhSt. The committee needed to be consistent and they were.
This is where I will disagree a little bit. Here's why: Last year Ohio St was ranked #2 going into the final weekend of games. After the final weekend (where they did not play) the Buckeyes moved DOWN to #3. Obviously still good enough to make the playoff, but they did move down in the rankings.
Alabama actually moved UP in the rankings without playing a game. They are the first team to go from out of the top 4 to being in the playoff without playing a game on the final weekend. Bama benefited from not making their conference championship game.
That's the part I have a little bit of a problem with. I don't think losing a conference championship game should be able to hurt a team when other teams don't have to play in them. I'd feel better about it if Bama were #4 going into the final weekend, and maintained their position without playing a game.
I'm satisfied with the result, as I think Alabama deserved to be in the playoff, but I don't like the way the committee got them there.