1. Offensive rebounding is detrimental to a teams defense. For the most part the best defenses do not emphasize Off. Reb. in order to shut down transition offense of their opponents. This has been widely accepted for a long time, the gains just don't outweigh the risks.
Overstated headline here, I think. Your point is a good one, but the exceptions on your list are instructive. Utah and Oklahoma City were third and first in offensive rebounding percentage, and second and fourth in rim protection – not a coincidence. I say you've overstated the point, even though these teams are in the minority; they are both trying to get an advantage by going against the grain in the way that they use their bigs.
2. Defensive rebounding doesn't correlate highly to great defense at least not in this current era. There appears to be more important things like defending field goal attempts aggressively that cause a team to rebound at lower rates. I believe this is because defending the 3 point line has become critical to a successful defense and big men are being forced to defend further and further from the hoop.
Not all defensive rebounds are created equal.
For example, if a team fouls a lot, they will likely drive up their defensive rebound percentage, since every team in the league has an overwhelming advantage in getting opponents' free throw rebounds.
But fouling a lot is very bad for your def. rating.
Free throw rebounds should be compiled separately from field-goal rebounds.
I post this mainly because so many people are hung up on rebounding. There are bigger things to worry about in today's game like speed (especially on defense), spacing, shooting and a team oriented mindset that are resulting in wins. It just isn't a league where the unskilled bangers of the past can or will find success.
One thing remains true in this new era of professional basketball: somehow, the defense has to complete the possession and get hold of the ball, whether through a rebound or some other way. What else is there? Turnovers, time running out, taking it out of the basket.