I fully believe the hesitation to take off is all the coaches fault. Look what they did to Denard. He hardly ever scrambled under this regime. He always looked hesitant to scramble. Instead he ran around behind the line of scrimmage and threw arm punts. There is a mountain of evidence pointing right at the coaches causing this problem.
But, but, but...... those aren't their types of QBs! They need slow white guys back there who don't have to be told not to run!