Small businesses aren't kittens, to be loved and protected regardless of anything. We fight shoplifting even though it disproportionately hurts individuals who rely on this business model - as opposed to big companies that have other, often legal, ways of stealing. We fight it because, like ads, it's a crappy business model.
Imagine if you Twitter ask you to pay per post or per view. Will you still use it ? Would that still be the Twitter we know of ? Many startups have for in their early stage considered ad money as one of their essential revenue stream and have built on it. Imagine if you have to pay everytime a dollar if you want to do a search and a lot more.
You're setting up a false dichotomy. Like advertising, your suggestion is one potential business model, but there are others. Thinking up another business model is a difficult problem, yes. But you can't stop ad blocking. Just like structural engineers have to deal with the fact that metals rust, website maintainers will have to deal with the fact that ad blocking is on its way towards ubiquity.
If twitter and google stopped alternatives would emerge without ad-supported business models and life would go on, there's no divine mandate they or what they do be valued at billions or even necessary forever.
