I don't believe that companies have the right to say that my user agent must run their ads. They can politely request that it does and I can tell my agent whether to show them or not.
True, but by the same measure your user agent can politely request a webpage and the server has the right to say 403 Forbidden. Nobody is required to play by the other parties rules here.
Exactly. The trouble is that companies want the benefits of being on the open web without the trade-offs. They're more than welcome to turn me down entirely, but they don't do that because that would have undesirable knock-on effects. So instead they try to make it sound like I have a moral obligation to render their ads.
