I don't agree with that at all. If it were true there would be more success at the QB position in the NFL.
Among the current starting QBs in NFL:
WVU (a mid-major when Smith was there)
Cincinnati (mid-major)
Louisville (a mid-major when Jackson was there)
Shephard College (D2)
Wyoming (G5)
Utah State (G5)
Fresno State (G5)
BYU (mid-major)
Along with solid, but unspectacular, P5 programs like Mississippi State, Wisconsin, Cal, Washington State, Texas Tech, Virginia Tech, Pitt, and Iowa State.
Or, more broadly, lets just look at a team. Lets take our region's team. Cincinnati roster includes players from Pitt, Toledo, Humboldt State (D2), Appy State, FAU, Princeton, Tulane, Northern Illinois, North Dakota State, and Wyoming.
Or lets look at the vaunted draft (yawn). Last year, there were 3 players from CUSA, 7 MACers, 5 Mountain West, 9 Sun Belters, and 10 AAC players drafted. Along with 10 I-AA and 2 D2 players.
ESPN, the focus of evil in the sports world, want you to think about only 20 or so teams. There is a lot of talent, for a lot of reasons, playing in other places.