I really want to know, how many people actually got addicted to gambling, because they played in the game corner of the older games. I've always spend my money in buying coins rather than playing slots, so I guess a lot of people did that, too.
If they were to remove them from ORAS, too, and replace it with some mini game, then I hope, they at least give you the option to still buy the coins, or at least remove the luck factor entirely from the mini games (in exchange they could make it a little bit harder). Considering even in the Voltorb Flip game there was an annoying luck factor, that can screw you over, if you had bad luck.