I think its the fact that, as you say, they are running a business.
And if its close to a race day and the fast group is full, they filter them down into the inters and even novice!
As i am a bit experienced, if someone shoves it up the inside of me, i wont (9 times out of 10) grab any front brake or panic.
For the less experienced fast boys and novice, it must be very intimidating!
Still love doing them though