I say this to save you future frustration and disappointment. First, your "concern" is, with respect, misplaced. That's their business, not yours. Second, that situation will not change while there are significant rewards simply for showing up for a roulette. I'm sure we'd all like the players you describe to get better, but as noted by many in this thread, they have no motivation to do so. You browbeating or shaming them will not change that.