From another post (can’t find a reply button to it) you said, “Do I take it, then, that part of the problem is conservatories training their students to be soloists rather than orchestral players?
(If so, I’m guessing that that’s a more common phenomenon for string students than for woodwind and brass.)”
My teacher, a Principal Flute of the MO, always made a distinction between an orchestral player and a soloist. He said repeatedly that most conservatory grads can toss of multiple concertos, but are unable to play a single orchestral solo correctly.
An irony seems to be, however, that orchestral playing can tend to make a performer more timid or take fewer risks as a soloist, which was my impression with him.