"He has had perhaps two good Drafts in the last dozen years..."
Um... you might want to check the drafts of some other teams. BB had a few duds in there, especially in the Maroney/Jackson period, but on the whole he's built championship contenders over and over again, largely through the draft. He certainly makes some curious picks, but you'd have to be crazy to say that the Patriots haven't been at least above average overall in his tenure.
First of all, he almost never misses in the first round, which is what really hurts other teams (and hurt especially before the new CBA). Maroney and/or Brandon Meriweather were probably the worst picks and even they made significant contributions on contending teams before flaming out. Moreover, and crucially, he hasn't missed on very high picks -- Seymour, Warren and Mayo were all building-block players. Dan Graham underwhelmed, but he was good enough to win with. Solder was a surprising but excellent pick. Mankins, Wilfork... You go down the line and with his top picks, he at worst gets a starting contributor for the duration of a rookie contract. You have to be a fan of another team, where the front office misses on guys like Justin Blackmon or Dion Jordan and sets the team back years, to understand how important this is.
Secondly, he consistently finds key contributors far down in the draft. Cannon, Dennard, Edelman, Slater, Cassel, David Givens, even guys like Ryan O'Callaghan -- these guys logged heavy snaps on contending teams.
Thirdly, he does more than just hit singles. He hits on guys with Pro Bowl/All-Pro talent fairly regularly. Gronkowski, Mankins, Seymour, Wilfork, Warren, Vollmer, Solder, Mayo, McCourty, Gostkowski even, Chandler Jones -- these are all cornerstone-type players. A bunch of them (Brady, Seymour, Mankins, Wilfork, Gronkowski) might be Hall of Fame candidates. You don't think your standards are a tad high?
I don't know how you can watch what he did last year, for instance -- taking an injury-devastated team and making a legit run with guys like Jamie Collins, Logan Ryan, Chris Jones, Joe Vellano, Ryan Allen, Sealver Siliga and even Duron (who?) Harmon playing key roles down the stretch -- and say that this guy doesn't know what he's doing on the player acquisition side. They went into last year's draft with what, a first, a third, and two sevenths? And they ended up getting eight or nine rookies to make major contributions toward a deep playoff run.
Seriously, try being a fan of, say, the Cleveland Browns. Most GMs miss on most picks. It's just the way things are. Belichick makes some questionable decisions, but man, compared to the way things used to be around here? Are you kidding? I go into every season expecting someone like Brandon Bolden or Kenbrell Thompkins to help them win games. Is anyone going to be surprised if Stephen Houston or Roy Finch ends up getting 100 carries this year en route to another division title? If James Morris ends up having a ten-tackle game at some point? We used to spend our Septembers watching first-rounders like Tebucky Jones (trying to play Bobby Grier's famed "massive press corner" role) and Andy Katzenmoyer fall on their faces, remember?