College D's don't do as much of that type stuff (some do but not the majority) so when these kids hit the NFL as far as QBs go it is a totally different Ballgame.
Plus just about everyone who is rushing the QB in the NFL is doing so in Olympic qualifying time for sprints. (even the huge lineman who can dash unbelievably fast over a short distance.) In college an opposing team might have 2 or 3 guys that fast. The so-called "slow guys" on the NFL teams are still faster than the majority of the players at college level so the QBs go from having 5 or more seconds on a drop back to barely 3 seconds and that difference is like comparing and aircraft carrier to a rowboat.
In college, at most a QB faces one or two NFL quality defensive players.
Of course in the NFL, they’re all NFL-quality players....Even the Jaguars would beat Alabama by 30 points.