If we used that attitude to review a draft, we would say we wouldn't have chosen again the 200 or so players before Tom Brady the year he came out. Hindsight is 20-20.
For what it's worth, I wanted Ed Reed that day. This isn't some opinion I formed after they started their NFL careers. If you look at my OP in this thread, I have no problem with Thomas. He's been a decent player for a while now.