Maybe I didn't read all the posts, but I don't remember anyone criticizing Howards defense. Most criticicism is in regard to his offense, which hasn't improved much in the last nine years. Thats just a fact. He has no game away from the basket. As far as offensive skill level goes, its not even close between Cousins and Howard. Cousins is far more skilled, and in my opinion, is still far from his ceiling. When you put up 30 and 20 in a game, thats not potential, its fact! At that point, the problem lies in consistency, not potential.
Defensively, I agree! Cousins will never be Howard, but then few are. But I believe Cousins can be a good defensive player with the right instruction. He's big enough and quick enough to guard centers in the league. There's no reason he can't make life a little tough for most of them. In my humble opinion, Cousins has two big flaws on defense. One is that when things start to go south, he forgets about defense, and hangs his head in disgust. The disgust might be understood, but quiting isn't. His other problem is that at times he tries to do too much, and doesn't get back into position when he has the chance. For instance he'll do a show defending the pick and roll, which is fine, but then he'll stay there going one on one with a PG, which is a lose/lose in most cases, and not get back to his man, who is generally cutting to the basket.
There are times when he stays with his hands up and holds position under the basket, and has had good success. Most of his defense can be improved with good decision makinig. Such as quit reaching in and getting little ticky tack fouls. It will be interesting to see how much Malone can change him.