Well. Barkley posterizes himself yet again, since his statement is absolutely wrong. Factually, and empyrically.
We have had great defensive games against good teams throughout the season, our pts/100 isn't even that horrible, and we have quality peripheral stats (blocks, eg).
Our defensive woes can also most obviously, and profoundly, be tied to the fact that we have the worst 5 hole in the entire league. If Charles wants to make an absolute statement, that would be one that might actually hold some salt.
Barkley is just being a donkey and getting in as many licks as he can, since our team will invariably improve as it currently stands, and certainly as we make further improvements over the next 2yrs.