I grew up on a very superstitious culture and just accepted it as a part of life. What I can't accept is that letting superstitions dictate on how you do things on your life, like gambling. You are relying your money on something unreliable,not really good for your wallet. But i get it, we can't help ourselves to believe that certain actions lead us to winning some cash. It's good but it also fucks with your psyche and concentration when you forgot to do your superstition and it leaves you wrong-footed and distracted, therefore making you prone to lose in gambling. I do not really do superstitions in gambling but I can't say that it doesn't have its uses but in the long run, it's luck with a little bit of skill and common sense that will win us the prize.
It looks like you are talking about poker because other types of gambling don't really need your concentration and the state of your psyche doesn't have much of effect on the outcome. I think to have superstitious beliefs is bad for you in general, like you said, because it makes you even more confused then you are. I think we should rely on our skills not on superstitions, but also we shouldn't forget that without luck no skills will help us to win in gambling.
Why other such types of gambling doesn't need any concentration psychologically? In few games, we need to concentrate over the analysis of the player/team we are betting on, and in others like dice, we still need our concentration levels to be high because
we might press the button wrongly and it may hurt if we lose. Being superstitious doesn't mean that anyone would be too much concentrative into what they have bet, but many things come into this. ~
But what if we win? I've seen a guy saying in PD chat that he hit the MAX button by mistake playing with 10% win chance and won. I don't remember exactly how much he won but it was more than 0.1. So, like I said, you don't really need concentration playing dice because there you can benefit from your mistake.
I have seen people not even watching the games they bet on, just because they think that if they would watch, the team/player might lose the match and they may lose the bet.
That's a superstition at its purest. And we all know that there is no sense in such behavior, but still it happens because gamblers would try anything to boost their luck. )