The question is what other attributes you "accidentally" filter by if you filter by school prestige. Even if you do bias your pool to individually better candidates on average, you may bias it in a lot of other ways.

If the purpose of the filtering is to reduce the pool to a size where humans with common sense can make sensible calls, then that CC graduate with 10+ years of competitor experience would likely be filtered out before common sense could suggest he might be good anyway.