No, it's not. When you're drafting in a league where around 40% of the first round picks are busts and that number only increases as the rounds go by, hitting on your picks consistently...even if you have to develop them...is NOT a losing proposition.
Go look at the best teams in the NFL. They don't hit on 100% of their picks. They just hit on the majority. If you do that, you'll be competitive. Because you can replace the players you can't pay with guys you've been developing. That's what the good teams do.
I think you just made his argument for him. Isn't he saying that drafting potential over more polished proven players is a mistake because of the high bust rate in the upper 1sr round? There's plenty of evidence to support both methods of drafting. Robert Quinn for potential and Chris Long for polished just on our team alone.