The OP and many other on this board suffer from a logical fallacy that assigns dubious causes to every effect, and sees patterns where there are none.
Monk has an off night -- that confirms for people suffering from this fallacy a host of false premises: 1. Cal is mortgaged to freshmen he's promised to get into the league. 2. Kentucky hasn't won every (or most) NCAA tournaments recently because Cal stuck with Harrison or Knight or Wall and Bledsoe or Randle too long instead of going to older (or younger, see Ulis 2015) players. 3. Cal is too inflexible and can't see the obvious time to bench a star freshman. And so on.
If Cal's system was to recruit 4 and 3 stars, redshirt them for a year and then play all 5-year seniors mixed in with a few graduate transfers, the same crowd would be disparaging him for not getting guys like Monk and the Harrison twins (who, after all, got Kentucky to back-to-back Final Fours.) If his system was to constantly go with the hot hand, and bench a leading scorer having an off night, the first time Kentucky lost these guys would be saying, "Why bench Monk? He was DUE to hit five or six in a row!"
The fact that people like this don't want to accept is basketball is not gravity or energy and it isn't controlled by a system of immutable physical rules. Kids have off nights. Refs blow calls. Things that have worked for coaches 50 times fail in a critical game.
Nothing -- NOTHING -- Cal or anybody else can do will assure that Kentucky wins every time -- or even every time the Cats are heavily favored and SHOULD win. That's basketball. Cal's system -- and his unmatched skill as a motivator and teacher -- gives the Cats a pretty good shot to be in the mix late in the tournament every year. After that, luck plays a part, guys have bad nights, other teams get on a freak roll, and so on.
If you can't take the lack of certitude, or the sense that it can all be controlled and defeat eliminated from the range of possibilities by the right series of coaching moves, basketball isn't for you.