Only sith deal in absolutes!
The second hand / used market hurts sales, but that's a "what aboutism" argument. It doesn't negate the problem of piracy.
More seriously. I know quite a few people from the Wii era who could afford a game and instead chose to pirate it, because it's free so they could instead buy ps3 games (before it gets hacked as well...).
-----------------------------------
I really don't like how this thread is going with "piracy doesn't hurt sales". I feel there's a lot of over simplification of the problem.
- "The pirates wouldn't have bought the games in the first place". Not everyone yes, and there are people who would have bought them. That's still a loss no matter how small it is.
- "They make more money in hardware". That may be true, although there's obviously no proof of that. But then it doesn't take into account that this money doesn't necessarily go to the developer of the game that was pirated. In this case, it goes to Nintendo, it won't go to an indie dev.
Does it hurt sales? Yes it does.
Is it in a proportion that matters? When it comes to Nintendo I don't think so.
Personally I care more about the online getting ruined by hacking than anything else. I do wish piracy wouldn't come so early, though.