Never once did I say it is an exact science.
Did you read all of what I have posted in this discussion? I ask because if you had I don't think you would ask me to explain guys like Ryan Leaf and Vince Young.
Of course there are bad picks every year. My only contention is what makes guys bad picks, and my argument is that fans cannot possibly know. For example, is it feasible that Jason Smith, on a different team, could have been successful? YES! But we will never know. That goes for every single "bust". Which truly raises the question: why are there draft busts?? What makes a bust? There are a million possible answers to that question, but yet only two outcomes - bust, or not a bust. I could go through and give an opinion on every single player as to whether they will make it in the NFL, or not. And I could end up being more right than anyone else in the world - because at the end of the day, it would just be getting lucky with a 50% chance for each player.
And the explanation is relatively simple: on each play, a CB and WR, LB and FB, G and DT, T and DE face off right? On every single play, you can declare a winner and loser, whether they are involved in the play or not (which is essentially what advanced metrics do). In order to be deemed a "good" player, you need to win more than you lose.
But in order for that to occur, someone needs to lose more than they win - thus now they are a bust.
So in every single draft, there will be "busts" and "gems", "good" picks, and "bad" picks. But a player drafted by the Patriots and a player drafted by the Jaguars are NOT given equal circumstances, and thus cannot be judged so easily.
My contention here is, aside from what all I just wrote, fans don't even get to meet these players, and yet we form opinions and criticize the FO of the Rams as if we know everything. It's dumb.
It's not an exact science, but it's very complex. There are a million factors that can go in to whether or not a kid is successful, and just because some guy behind a computer said Vince Young would be a bust, doesn't mean he has any clue as to WHY Vince Young became a bust.