Keeping in mind that correlation is not causation, so you can't just say, "These thirteen QBs failed who came from the spread/Air raid offense".. Of course there are some QBs who aren't successful in the NFL, but is it because they couldn't manage the 3 Step Drop? Or is it because their numbers were inflated in college due to superior coaching and athletes, or because their skills were better suited for college? Did Johnny Manziel or Tim Tebow fail because they couldn't handle the 3 step drop Shotgun, or because they didn't have the arm (Tebow), or size, demeanor and work habits (Manziel) to be successful, and they just happened to come from spread attacks prior?

This is not necessarily argumentative, if you have the evidence I'm interested in seeing it and willing to reconsider my option, but in my experience most people who say, "there is evidence of X," really mean that there are examples of it, and due to confirmation bias they focus on those examples instead of counter examples such as Mahomes (Air Raid), Alex Smith, Cam Newton, Deshawn Watson, Jared Goff, (Spread), etc.,