College sports, unlike the its professional counterparts, does not enjoy the benefit of having a small enough set of teams to simply make a playoff out of every conference champion. Instead, they stick to traditions, metrics, committees, and every which measure the powers that be feel comfortable with at the moment.*
College basketball is well ahead of college football on that front, having found a not-perfect, but pretty consistent measure of who get to play for the sport’s biggest prize: Every conference champion is in**.
After rewarding every team that won their conference, the committee picks the remaining teams based on a set of metrics that are out in the open for everyone to see, and rarely do they deviate from that formula.