I think the "bad defensive coach" stuff is a bit overblown. There's no way the 2012 team tied OSU and MSU for a conference title without being pretty good defensively. Both of those teams had far more talent than we did, and yet we managed to tie them and beat both at home.
I'd also say JB's first few teams (including the tourney team of 2009) played solid defense, and so did the 2011 tourney team. We absolutely crushed a far more athletic Tennessee team in the tourney, and took Duke right to the brink - they had no answer for the 1-3-1.
2012-2013 ushered in a whole new era of Michigan basketball, where we literally had more offensive talent than any team we played. The team was young, and it's hard to get great effort on the defensive end when your players know they can fall back on their offense and win almost any game.
Last year was somewhat similar. For a "bad" defensive team, we went 15-3 in the Big Ten and won it by three games, which is almost unheard of. And it was a strong conference. Was our defense great? No. Was it awful? I don't know how you go 15-3 in the best conference in the country if your defense is awful.