The reason I think it's potentially a social issue is: In that situation you have a small group of people effectively curating the internet (deciding which sites are useable and which sites are not) for a large portion of the population.

More to the point, you're potentially giving a private business' stakeholders the right to decide which media outlets are accessible for certain people, which news sites are useable, etc. Is it possible that this power will be used in a completely benign fashion? Sure, it's possible. But I think it's also worth considering the possibility that these decisions would end up amounting to censorship of certain views.

Your argument about market-choice is a fair one, except that cost is a limiting factor for large portions of the population. We're NOT talking about even-handed limitation of supply in accordance with your ability to pay. We're NOT talking about cost as the outcome of supply and demand; we're talking about choice and access to unfiltered information as the outcome of whether or not you can happen to be rich or poor. If that's not a social issue, I don't know what is.