I don't know if "market inefficiency" is the right way to express the point, but I definitely think Belichick views the draft very differently from how many other teams tend to view it, and it's not just the last year. I don't think it's GFIN, since some of the things the team does are definitely long term focused. I think Belichick is just not convinced of the value in draft picks, and much behavior that we've seen -- preferring a back up QB to seemingly "high" picks, trading down, using a 1st round pick to trade for a position where we already had depth (before Jules got hurt of course), taking guys in the draft that seem like they will be available later -- backs this up. I think he views them as lottery tickets at best, despite your best efforts, and he'd rather do things his way than gamble.
Part of it is that the team rarely picks in a spot where it would be highly invested in the draft anyway. He has had exactly one top 10 pick ever -- Mayo at 10 -- and so he is almost never picking a guy where you have a super high confidence level that he'll be a multi-year starter, so he's had to adapt. In retrospect, sometimes you hit with pick 32, but certainly not always. When is the last time that there's been a guy available for the Patriots who didn't have significant question marks or wasn't a gamble? Maybe Solder, and they took him at 17. Even when you "hit," you can hit on a guy who doesn't fit right.