I disagree with this. The situation in the current NFL is that there is free agency. That means that a team doesn't necessarily keep the players it drafts. They sign their second contract with someone else. Also the NFL CBA has limited the number of draft picks, so there are no longer 12 or 16 or more rounds. The value of draft capital has risen. Teams can't draft a Johnny Unitas in the 9th or a Roger Staubach in the 10th round. Furthermore there is far less stability in the coaching ranks. A coaching staff that starts to develop a project QB could be fired years before the project shows anything.
So given the Bills situation, where the coach is on a hot seat (at least in many fans view) and the incumbent starting QB is mediocre, it doesn't help your team in the "hot pocket" era to draft a guy who is considered "years away, if ever." Even if he "gets it" and develops quicker than expected, he may only start getting on the field in the final year of his first deal. And then a team can be faced with the Brock Osweiler decision. Some other team may inflate the price to keep a guy who is still a suspect and a project and who no one knows is for real or not.
But not every situation is the same. A team with some stability and that already has a Hall-of-Famer starting (Brady, Favre, Peyton, etc.) can — and should — draft development QBs. It's smart to have Aaron Rodgers developing right behind Brett Favre when you know Favre isn't going to play forever.
And we've all seen the Rams situation, which is reminiscent of the Bills the year they drafted EJM. They have a veteran QB who looks good in practice (apparently) and not so much in games — and both are former UH QBs. (Though for the Bills, the terrible KK tripped on a rubber mat and disappeared.) They got a 1st round rookie and an unknown guy, and some people say they like the unknown guy more. (Thad Lewis had a higher QB rating than EJM; we're set!)