Because they are not comparable programs. I’ll admit Kentucky/Calipari is an extreme example. But let’s say Rick Pitino two months ago had been offered Illinois and Oregon State? Which one do you think he’s taking? I’m thinking there’s a 98% chance it’s Illinois.
So you can't explain it without pretending it's a truism. "it's just true".
Calipari was an extreme example in that I couldn't have possibly picked a better example to undercut your point. He's the exact opposite of what you're claiming. He's had similarly good results everywhere he's coached, from mid-majors to blue bloods.
I have no idea which one Rick Pitino would take, but that's not the discussion we're having either. I know you do this "why would anyone pass up Illinois?" thing every single time we have a coaching search and have typically ended up with that looking pretty silly, though. Why would Brad Stevens pass on Illinois to stay at Butler, or Shaka Smart to stay at VCU? Because it's not 1988 or 2001.
Do you think Rick Pitino would definitely have better results at Illinois than at Oregon State simply because Illinois has a better history? I don't. I think Pitino is likely to have similar success at either place, because he's a good coach.