We don't have to make a blanket statement that covers all cases. I don't see how this is a slippery slope when there is so much friction to get even one of these industries banned from advertising. Do you really think politicians will ban CAR advertisements? Let's be reasonable about this

EDIT - Okay I think I see a concrete reason why gambling advertising should be illegal. The gambling industry makes money by negatively affecting people i.e. gambling wins if you lose. That's literally it. The gambling industry does not make money when their users win. They are specifically advertising so that more users lose. The car industry makes money by providing you a utility. The car industry is not advertising so that more people die in car crashes. But gambling on the other hand _is_ advertising to get more people to lose.