1.) It doesn't gain any traction due to players being ineffective
2.) It gains some niche/gimmick offense that teams adopt to throw people off
3.) It starts a similar trajectory as the NBA with position-less players. If every RB and WR on your team also have QB backgrounds, the trickery could be mind numbing.

There could be flea flicker plays treated like triple option offenses.
Option 1, QB throws a quick slant to a TE.
Option 2, QB Hand-off to crossing WR who can either run it, or throw it to a streaking slot receiver
Option 3, Crossing WR pitches it to end-around WR, who either runs it across field, or throws it to a TE at the end of his slant
Option 4, End-Around WR pitches it back to QB (standard flea flicker), who bombs it.


If both of those WRs have QB background and can make more than 1 scripted throw, it'd be nuts.