OK, let's pretend that there are ZERO logistical concerns.....I still wouldn't like an expanded playoffs and don't think it's necessary. College football has bar none the best regular season in sports, there are basically elimination games every weekend. I love the fact that there is so little margin for error and that every game is critical. How many truly competitive games do teams like Ohio State, Alabama, Clemson and Oklahoma play every year? Three? Four? Maybe five in some cases? I don't really want a system where a team can lose two of those and still be basically locked into a playoff spot. That's what makes the regular season so good, no team can afford to slip up much. No system is absolutely perfect but there isn't much wrong with the system currently in place. With very few exceptions, those additional games would be games that don't really need to be played because the pecking order is decided in the regular season.
If Alabama loses to Auburn and LSU they don't deserve a chance to play for a national championship IMO. Ditto for Wisconsin if they lose to Ohio State and Iowa. This year Oklahoma wasn't even competitive against LSU and now we'd be talking about Baylor being a playoff team, and they had two tries against OU and lost both. In most every year it'd just be adding games that aren't necessary to determine a champion.
The NCAA basketball tournament is a fun event but the fact that basically every decent team makes the tournament does make the regular season kind of an afterthought. What is the intrigue in a February matchup between two really good teams? The outcomes are kind of irrelevant because come March every team starts over and plays a single elimination tournament, and that's really all the casual fan cares about . Outside of TCU games I for the most part don't even watch college basketball, I just wait until mid-March.