I'm going to present a different approach to answer some of this...And this is a Wholly non scientific opinion from playing and watching students attempt to play this crazy game.
Why do Monday qualifiers struggle to compete after normally shooting a crazy low score to get in an event?
Most of these players have a deep competitive background and resume, and are obviously playing well to shoot the qualifying score on Mondays.
One of the big reasons IMO is the course setup for tour courses. In particular, the hole locations being 3-4 steps from edges quite often, which is even tighter than when I played.
The hole locations create an issue that short siding yourself with the speeds of the greens and yes, whatever rough there is make getting up and down from short side much more difficult.
The atmosphere plays a part for some, but the difference between setups for most qualifying courses and the actual event are staggering.
Some events are pretty easy but there are some nasty hole locations where being just a fraction off can create that one mistake that can kill a round