Yes, at the highest level of professional sports, etc. I see a clear financial motive to cheat (cue reference to the amorality of corporations), but some subset of people cheat all the way down that hierarchy in sports/cards/etc.
/slightly OT, but thematically in line, I think:
I'm a rather avid amateur billiards player (there's no money in pool in the US anymore, not that I can even compete with the pros - I'm better at making money with a keyboard) and I routinely see a (admittedly small, probably around 1%, but unchanging as players come and go) percentage of amateur players that clearly, actively want to cheat as long as they can get away with it.
The actual expected value for their cheating is terrible. I play in a couple of leagues where, if, by chance, you get first place, you'll get ~$1000, having paid ~$256 in table time (and 16 weeks of play) to get to that last match.
It's just a game! Isn't the whole point, and fun, and glory of winning a game actually winning by the restrictions placed on you by the rules? I can beat Tiger Woods by hitting him in the temple with an icepick, but why? The rules are what make the game challenging.
I guess I just don't get it, if I foul in a pool game I'll call myself on it, because if I didn't I wouldn't walk away from it thinking I won. I'd think I cheated and I would feel terrible about it.
Reiterating my opening sentence, I just do not understand people who cheat on games.