Actually, no, I'm not. I'm not even addressing it - my only point is that BPG should not be a hugely important metric when choosing between defensive Cs. I was isolating BPG to illustrate that this single part of the game is not going to be a determining factor in whether you're a good or bad defensive team. If you want a real world example we can point to Javale McGee and Marc Gasol. One blocks shots, and one is a good defender...both alter shots.
Honestly, I have no clue how Marc Gasol won defensive player of the year. He isn't even the most critical defender on his own team, I'm guessing rebounding played a pretty large role in it since thats part of "defense". He also does block almost as many shots as Javale.
Tyson Chandler blocks shots and is a good defender. I'd even say the top 10 in BPG are some of the better defenders in basketball, which makes BPG a relevant stat.
Ibaka - Don't see anyone arguing this
Sanders - Or this
Hibbert - Or this
Duncan - Or this
Howard - Or this
Brook Lopez - Nets are better with him on the court (3 points)
Javale - Nuggets better with him off the court (2 points) Also, the Nuggets aren't known for their defense, nor are the Nets.
Josh Smith - Not really arguable.
Bismack Biyombo - Don't watch the Bobcats. Pretty sure everyone outside of Kemba sucks.
Anthony Davis - Obvious.
Marc Gasol - So it appears he does block shots, hm.
That stats seem to suggest that BPG does equate to good defense. (After all, most blocks come from help side D and rotations.) I wouldn't say its the most important but I'd say it has more relevance than you state.