It's frustrating for quarterback prospects to be drafted below where they think they should go, but it's far from a professional death sentence. Often, those future NFL signal-callers who are taken later than they should be based on talent and tape wind up in better situations than if they would have been taken earlier.
Dan Marino dropped to 27th in the 1983 draft but wound up with Don Shula as his head coach. Tom Brady famously wasn't picked until the 199th selection in the 2000 draft, but who knows how he would have developed without Bill Belichick?