Because you have a flawed view of what the expected outcomes are. No matter who you have ranked higher in the RPI, the same teams are winning over the past decade.
Then don't just use the RPI.
When was the last time an ISR # 1 won the CWS?
How about the # 1 national seed?
Or the # 1 team in the Baseball America poll?
I've said this since day one on this board. It doesn't matter what standard you use. The 'best' team by any standard rarely, if ever, wins the College World Series.
But you think it's all predictable. That's why you're fleecing your friends at the MGM sports book every year, right?