I think I might be more inclined to agree with you if Harris & Sims were JB recruits. They were obviously on the roster during 09 & 10, and were the best defenders on the team in my view.
Additionally, when JB has a choice to prioritize motor/intensity/defense OR offense, he goes with offense, and that's not going to change in my opinion. To think we're actually worse at defense this year in relation to the last 3 is a scary thought indeed. John Beilein is simply not a good defensive coach, and I have no faith that our defense will ever be better than average under his regime.