It's not useless. If you see a friend or a relative, would you tell them to buy bitcoin straight up because you have it? Or would you rather explain the risk as well? I bet you would choose the latter since you don't want them to berate you when the price falls. That's the point of the ban. There are still people who pass by that area where the ad was placed and all over the world who do not know about bitcoin. Irresponsible investment adverts like that are dangerous to both newbies and that will affect bitcoin.