According to Synergy Sports, Joakim shouldn't even be on this list.
Tim Duncan is warranted. He ranked 57th defensively.
Perk ranked 80th.
Joakim ranked 240th defensively overall. 
Boozer ranked 280th.
Paul George ranked 258th.
Just wow.
Popularity contest....there's just got to be more that's looked at with these rankings than just whether a coach likes a player.
But I'm not a coach, so perhaps they see something I don't.
Call me crazy, but I don't think the defensive teams are all that bad this year.
-LeBron belongs on the first team and has the athleticism to defend all five positions at times.
-Tony Allen is the closest thing to a stopper in the NBA.
-Dwight Howard's teams defensive rating is worse than Chandler's, sure. But his individual defensive rating is better. He also outrebounds Chandler by around 5 a game. Finishing a defensive possession with a rebound is key. The contest is close, but my vote (I don't have one) would be Howard.
-Chris Paul and Rajon Rondo are closer on defense than everyone here thinks. I know it is a sin to compliment CP3 on this forum, but he isn't terrible and is actually quite good on D. All point guards allow blow bys from time to time. It is the quickest position on the floor and one where the PG has screens and the entire floor to work with. Either one is fine. I'd personally pick Rondo but CP3 is quite close.
-Ibaka over KG is pretty criminal. Ibaka sells himself out of position with frequency chasing blocked shots. Garnett is far better. But in fairness, Garnett played Center all year anyway, not Power Forward.
The second team is similarly defensible. Igoudala is better than Kobe, but the 76ers play Evan Turner at SG and Igoudala at SF.
Both teams are pretty reasonable.
-Duncan is still a quality defender. Declining but still good.
-Bradley played too little to begin the year and is too off the radar. He cracked 20 minutes only once in the Celtics first 13 games (that's about 20% of their games in a shortened year). Can't be a non-factor for 20% of games and be a contender for this type of award. He'll be there next year.
-Maybe Noah's D stats are low from fatigue in covering for Boozer?
-I've never been that excited about Perk as a defender. He is a great low block defender, but the NBA is shifting in a different direction. Fewer teams have elite centers, so a quick defensive center who can chase guards and forwards (like Dwight and Chandler) is much more valuable.
-Surprised to see that on Paul George. Maybe the coaches (and myself) are tricked by his defensive potential? He is tall, has long arms, and great speed.
Nice research, GreenFaith.