Just because Darius Miles might have had higher expectations doesn't mean Brown has minimal expectations. The two points do not relate to each other. A #3 pick never ever has minimal expectations. Each one is a top end prospect/selection because a lot is expected of him.
I do give you credit for citing your sources, though.
Edit: Your last point about being booed is really misleading. You are well aware it wasn't Brown that was booed, it was the fact that we didn't trade the pick for Jimmy Butler. Others, like myself, preferred Dunn; some even liked Bender or Murray, but the Brown selection was universally seen as decent, if not exciting.