Vernon Gholston and Quinton Coples, two classic underachievers.
There are college guys who come into the league and they just don't have the physical ability to perform at a high level, the competition is too fierce, unlike college they are facing the best players in the world every week and often times guys who are physically superior. That was NOT the case with Gholston or Coples.
Both fall into the "looks like Tarzan, plays like Jane" category. For whatever reason something was lacking for these guys mentally, whether they were lazy, didn't have a real passion for football, were only in it for the check or simply didn't have the required courage to play in a MANS LEAGUE, it could be one of those things, a combination of those things, or something else of the mental variety, but physically they both had what it takes to compete in this league at a high level, thats why they were drafted so high. When guys like this washout, and its not due to injuries, its always mental. Thats why the draft is such an inexact science. If all it required was measurables to know which guys were going to succeed at the next level, NFL GM's would have a much higher batting average with these picks. Its the mental part thats hard to predict.
Don't misunderstand me, both of these guys had red flags in that regard, there were whispers about both guys taking plays off, both would have went even higher in the draft if not for concerns about their motors, so its not like there was no indication of this whatsoever, but the physical talent was BLUE-CHIP from the word GO, physically both had an "IMPACT PLAYER" ceiling, so they were going to be first round picks regardless of the concerns, then you hope being in an NFL environment can bring out the best in them. Normally it fails and it failed miserably with both of these underachievers.
As boxing trainer Teddy Atlas likes to say; people who are born round don't die square.
But guys fool you all the time in the draft too. They swear they are ready to set the world on fire if you take them in the first round, but you never know how a 21 year old is going to react to hitting the lottery until he hits it. I've long contended that its human nature to get lazy and disinterested when you suddenly come into that kind of money. I try to imagine myself at 21, if someone suddenly gave me a few million dollars. Heck, I might have been dead before I reached 30, and for sure I would have had zero incentive to work hard at a job that was physically demanding and punishing. I wouldn't even sit behind a desk for 8 hours pushing paper. You couldn't have gotten me to do anything that interfered with my leisure time. So I personally think the first round picks who stay hungry and do all of the things it takes to be great in this league are abnormal in a sense, they are the aberrations in society, not the underachievers.
Anyway, thats my theory on why so many first round picks go bust. GM's are not throwing those picks away on guys who don't have the physical makeup to excel at the next level. Physically they are picking the right guys. Its just so damn hard to discern which guys are going to STAY HUNGRY after they hit the lottery.