Saying a winner-takes-all contest is "zero sum" in any sense is utterly nonsensical, as it's clearly not zero sum since one group wins $1,000,000.
Also, "one guy" doesn't necessarily get all of it, as team co-operation is implicitly encouraged as it increases the chances of winning. Additionally, the game is strictly skill-based, so the more skilled you are the more likely you are to win, which may encourage you to work in the contest. And that's excluding all the additional externalities involved.
Ok, so call it "fixed sum" or whatever else is technically correct - that's the point I'm trying to make. If one guy wins, another guy necessarily loses. That's not true in plenty of other things.
> the more skilled you are the more likely you are to win
Yes, but the second and third guys are quite skilled too, and win nothing (and yes, we are excluding the externalities since we're talking about the general case, not this specific one).
Also, "one guy" doesn't necessarily get all of it, as team co-operation is implicitly encouraged as it increases the chances of winning. Additionally, the game is strictly skill-based, so the more skilled you are the more likely you are to win, which may encourage you to work in the contest. And that's excluding all the additional externalities involved.