[pron]

I would put it another way. Any legislation against doing something is almost always motivated by someone's desire to do that very thing. Legislation is usually a battle of interests where the legislator, ideally, wants to protect the overall interests of the public when they conflict with narrower private interests. When the narrower interests belong to powerful groups, you often expect to see some struggle, and if the private interests have a way of making the regulation seem more intrusive and annoying than the harm it's intended to cause, they would take advantage of that to sway the public in their favour.

So legislators do expect such a struggle, and the shape it takes may be partly their fault, but it's clearly not all their fault. The more power the private interests have, the more likely they are to find some way to fight the regulation. They will certainly do everything they can to convince the public that the legislators are bad at regulation.

In this particular case, however, websites showing banners are also harming themselves as their competitors now have an interest in not showing banners and offering a better experience -- i.e. the regulation makes it worthwhile not to display banners in competitive situations. So we'll see how this all turns out.