When the demand is that high though, they know they will sell out. So it's in their best interest to make sure customers feel they were treated fairly. That's why you adapt to certain things (like certain Toys becoming in high demand).
I agree with you in a very basic sense, the goal is to sell all your stock. Without knowing what demand is, you would be crazy to set a limit to how many someone can buy. Ultimately, even if if it's only ONE person buying all of it, they are still getting paid. Who cares where the money comes from.
But in cases likes this, they should know what the demand is. Since Amazon is a major international online/warehouse company, I don't know how feasible it is to implement a 1 per customer, since no where on the site do they do that. Whereas Retail stores CAN implement it -- and should (as did Target with Rosie).
So maybe stupid is the wrong word to use. Really, I was just saying the guy shouldn't be raging out at the people that bought it, and should instead ask why companies aren't implementing 1 per customer. Why they aren't setting limits. Customers are only buying what they are allowed to. In the case of Amazon, maybe it's not feasible or again, realistic to have customer limits. So yeah.
Still, I think his anger was misguided and should have been directed at Nintendo for choking supply on purpose, and retailers for not setting limits/policies, rather then getting mad at people for buying what they could.