Exactly. I am a Buffalo Bills fan and we have had well-documented issues at QB. Our defense and skill positions may be great this year because we have less money tied up at the QB position than most teams, so more money to spend on the rest of the roster.
Say we have $5 million tied up at QB this year. That could get you a very mediocre pro-style QB like Matt Cassel or EJ Manuel, or it could get you Tyrod Taylor and Justin Thomas, star QBs in your system who commands next to nothing on the free market. Now if you want to try to sign guys who would be very good in either a pro-style system or an option system like Russell Wilson, Colin Kaepernick, etc, then the argument about the inability to stock 3 QBs due to money makes sense.
GT has been able to get away with a lack of a good passing game for years. Obviously our offense is better when we can pass, but we can still run a pretty good offense with guys like Nesbitt and Washington throwing the ball. I guess the real question would be: how good would the passing game need to be for an option offense to succeed in the NFL? With the defense's focus being on the run game, the windows are bigger/more single coverage/etc in an option offense than a pro-style offense. Would Tyrod Taylor, who is not quite accurate enough to run a pro-style system in the NFL, be accurate enough to consistently execute passes from an option system? My guess is yes.
So if you can overspend at non-QB positions due to your QB cap hit being small AND get star-level production from your QB, I think it could be a genius move.