Michael Lewis showed that big-league baseball coaches and general managers are nearly all idiots (or at least were until he wrote his book exposing them, at which point a few non-idiots got hired, but most idiots kept their jobs), so it's not necessarily totally implausible that NBA coaches are all idiots.

Out of curiosity, since I don't know anything about basketball, how do you beat a full-court press, and why isn't it a good idea to at least try to stop people from getting down the court?

Like Gladwell points out, you have to be extremely well-conditioned to press for a whole game. It takes a lot out of you. So it could be counter-productive if your team isn't in excellent shape, because a poorly executed press (say, if your team is tired) makes it easy for the offense to just blow by you and hit layups.

That said, a team of good ball-handlers can beat a strong press if they stay calm and pass well. Patience and poise.

(Which is probably why the press is so effective in younger leagues: players at that age get frantic under pressure and just don't have the dexterity/skill to keep the ball under control)

NBA coaches could all be idiots, but my point is that this article doesn't show it.

One way to think of a full-court press is as a way of spreading resources thinly. You can beat it by handling and passing the ball well. On a thinly defended court, this leads to a lot of easy baskets because there's so much open space.

That seems to be the conventional wisdom. The conventional wisdom is probably right for teams that haven't specifically prepared to constantly press.

Are there any statistics on the effectiveness of a full-game full-court press done by a team that has conditioned itself to press for the entire game? I'd love to see some actual data on this.

The key here is that the data must be only from those (few) teams that have conditioned themselves appropriately. Otherwise, it's measuring the wrong thing.