That's just laziness. In high school, especially in Canada, he had to have been more athletic than pretty much everyone he played against, so that's not a reason.
Nash simply doesn't work hard enough on the defensive end. Nobody else gets these "he just can't do it" excuses.
fukk outta here. He's a terrible defender, a college scout went to watch him play and the first thing out of his mouth after the game was "you're the worst defender I've ever seen." He's not lazy, he can't defend. Some people are horrible at defense. Defense takes much more than effort, it also takes a particular talent, and a certain instinct. Just like rebounding, where you don't automatically lead the league because you're big and work hard. I can't even count the number of hard working, determined players I torched in the post when I played ball. Some people just ain't got it.
And I have no fukking idea what you mean about "he just can't do it" excuses. You're arguing with some made up point. I'm not making any excuses, I'm saying he's limited as a defender, and that's not going to change. He sucks at it.