Yes, I think gamblers like to blame others. And these are of course the players and or teams that are responsible for the gamblers losing their bet. Still, there is only one person you should blame and that is the gambler himself, as he himself made the decision to bet money. If you can't stand losing once, it's better not to bet any money at all, then you can't lose in the end.
Not all mate because I'm more inclined to believe that there are a lot more gamblers who takes and accepts their loss in a calm way and will not go in such ways like blaming others if they lost the bet, including the players or fighters where they bet on because that's the part of the bet. You yourself as a gambler know that even if the team you bet on got a much higher chance, it doesn't mean that they are the ones who will in the end and that's why there's a term upset.