If you asked me whether the SEC deserves more spots in the CFP than some of the other conferences, I would say they certainly do based on their history of success in the post season in general (representation in 8 of the last 10 Natty games, winning 6 of them), but I don't think they and the B1G are so much better that they deserve to crowd out every other conference. The bias rears its head when teams that have not been tested are given a pass because they are in the SEC (or bound for it whenever the ACC breaks up...looking at you Miami/Clemson). Performance on the field should continue to matter the most and SOS should matter as well, but I'm not sure I saw that reflected by the committee throughout the year.
I can see how you could say the SEC has earned the favorable treatment, but I don't know that they are as dominant as they once were and some of the rust is showing. For example, Nick Saban's 'Bama teams were in six of those championship games over the last ten years and won half of those national titles and with him no longer at the helm Alabama has taken a non-trivial step back. Last year the SEC was not represented in the NC game at all and, while Saban and many of his predecessors had a dynasties, it's not like 'Bama is guaranteed to always be some kind of unbeatable program. Over the 10 years before Saban arrived on campus Alabama averaged 5 losses per year AND they were hit with probation in both the 90's and early 2000's. Flash forward to this season where 'Bama lost to Vandy suggests to me that we should stop pretending it's the same 'Bama team that was lead by Saban for 16 years. Dynasties come and go over time and 'Bama is definitely on a downward trend.
The SEC doesn't really play meaningful games OOC so we don't really know how solid those teams are until the post season. Heaven knows we'll have a lot of opportunities to see SEC/B1G teams play in the CFP this year so it won't be a secret for long.