Hypothetically, if we get a 4* guy, we expect him to be a star, because his rating is much higher than our average player's. If he then turns out not to be a star, he bag on him, even if overall he is a good player.
If Alabama gets the same 4* guy, they know he is going to have to work hard just to see the field, so if he turns out to be a contributor, he meets expectations.