I guess it would boil down to how much it would cost (in actual costs plus the cost of making a potentially bad PR move). I would be really surprised to find out the casino industry hasn't done any inquiry into the idea and decided against it already, because on its face it seems logical if they want to attract customers. I wouldn't think the industry would start up daycare operations for any altruistic reasons

ETA other people have posted that some local casinos in Vegas do this already, so it must make sense for them.