Chinese gambler will surely believe on this, and they have this tradition in almost everything not just in gambling.
There's nothing wrong if you have this ritual before you gamble, what is wrong here is if you depend on that belief and spend too much money. This is still gambling, and luck will still be the main reason why we are winning. We have this kind of tradition as well, and there's nothing to lose if you believe on this sometimes.
Believing in these kind of things won't get you hurt either because it's just a belief and we do have our distinctive body language that will make us comfortable. In the same thought, I think that some gamblers that are saying some rituals prior the activity is not a sign that they are relying on it but I see it as their way to make them more confident on the activity and as I said, will make them play more comfortable.
As long you dont hurt others or making yourself hurt or something in between two then i dont see anything wrong with it.People are just too judgemental on what others been doing.
Just mind your own business and proceed into your own actions rather than on discriminating or teasing someones belief.If they dont hurt someone then it is really that still considerable.