I have watched out de's for several years closely because I coach that position. To say they are bad is an understatement. Physically they have okay tools, but they are either really dumb or are taught some new technique that nobody else in the world plays.
Pass Rushing
They Rush the whole man
This means that they try to bull straight through the guy. Instead of pressing the edge and getting the corner shortened, we try to run through the guy and we are small.
(Jacques actually had one decent speed rush but missed the qb and he ran for 45)
They do not understand lane integrity
When they rush upfield they abandon their lanes and chase at the wrong time. their positioning for a counter underneath versus a mobile qb isn't the same as a statue.
You can quickly counter move against a statue qb or one that is running away and trail, but against a really mobile guy an instant inside move when he is free otherwise in the pocket is a big scramble waiting to happen.
They don't seem to know if its run or pass before the play.
75% of the time a college fb player should know if its run or pass before the ball is snapped. we seem unsure and tentative.
They have non-aggressive hands
Decent linemen lock us up and we do little to nothing to get them off. We just try to run through the blocker.