Trying to figure out what a 21-22 year old is going to grow to be like is difficult. Mix in a kid that's likely been treated like "the man" since being young, he's been coached into creating a perception of himself and then give him money - now you've got an even more difficult thing to try and figure out.
Not an easy thing to do and is the reason that they spend soooo much time looking into these guys. Do you think they don't spend massive amounts of time looking into the character of these potential draftees?