And why is that? The rest of society has deemed it a ligitimate business. So you simply don't like gambling and that's why you want them to eat it? Not a very strong argument.
It's more that I think the activity of promoting gambling is one of getting your customers to eat it (It's advertised as a game of stakes, it's really just skimming transaction fees), so I don't mind it if what goes around comes around once in a while.