It's not so much the volume of runs as who's doing it. If you are the QB (black or white, as I've shown) , and most of your time is spent running parallel to the LOS, then pitching at the last minute, or maybe keeping it if they play the left halfback, you're not going to make it in the NFL.
I can really only speak to the period from maybe 1970 to today, but there are PLENTY of colleges that ran dropback passing schemes, and they produce NFL quarterbacks. Schools like Miami, BYU, and Purdue are feeder systems for the NFL and always have been. Others, like Michigan, weren't before, but scrapped their option systems and went to pro set, and have a string of drafted and successful QBs.
That's what the NFL wants. That's what the NFL has always wanted. There are wildly successful universities that produce fine NCAA QBs that are utter flops in the NFL. Florida, FSU, Oklahoma, Texas and Nebraska come to mind. Lotta NFL never weres, flops and mediocrity there. THEY DON'T PRODUCE WHAT THE NFL WANTS.