What I understand in regards to this is that the market ups and down doesn't seem to affect the gambling process because at every slightest chances people tend to gamble and whichever way seems favourable to them so they can gamble when the market is either down or goes up. Meanwhile for those that make use of crypto casinos they tend to gamble when the market is down cause they choose not to be in loss.
That’s not really what OP is trying to say. What they mean is when the market is down, interest in trading or investing drops. So people shift to gambling instead. And that leads to higher volume in casinos, which is actually good for the gambling industry.