If a player loses a bunch of money to a bookie they may be inclined to throw a game for him to make up for it. I used to think you should be able to bet on your team (as Mike Florio has stated) but I disagree with that now for the same reasons. Too many things can happen when players are betting on games and most of them are just bad.
Well here's the thing. With sports gambling legal in all 50 states and apps like DraftKings and FanDuel now prevalent, they shouldn't even be betting with bookies. Bet on those apps that take your money the moment you place the bet. That way you're less inclined to risk and there's no way to make up for it by throwing a game.