Drafting a CB @10

What is with this sudden afformation that rookie corners cant play in this league? all the big time corners in this league have been playing from day 1 and they all didnt come from the first round, some guys just have "it"...not it remains to be seen if the guy we draft has "it" like any rookie, you wont know until camp...Rookie recievers arent supposed to have big impacts and we seen were that went (Holt, Bolden, Colston, Moss....) its not an exact science either way, but its most definetly not a fact, rookie corners cant help a team.