There is a concept that there is an implicit moral contract whereby if a site has ads, then you must view those ads to view the website. There is a certain logic to the idea. But as far as product is concerned, I don't think it holds up. The basic idea is that if you consume what they are providing, you must also consume some advertisements that the content provider places on the site.
Let's see how logical and reasonable that concept works when applied to, say, produce.
Suddenly, No company charges for the strawberries, but some strawberry distributors have contracts with Dried Goat Turds Inc., and when they sell you strawberries, they will also include a selection of random dried goat turds, and they get paid based on how many of these dried goat turds you eat.
Like a good customer you are expected to finish all your goat turds. Nobody ever wants to eat goat turds. They taste like, well, goat turds. Sometimes, goat turds make you sick. Too bad. That's the price you pay for strawberries.
Blocking ads is like ignoring and not eating these goat turds, and only eating the strawberries. People see you have a goat turd filter, and call you a strawberry thief.
But in such a world- is it immoral to not eat goat turds? I say no; I say that if a company provides you with a bundled product, free or otherwise, you are perfectly free to pick and choose what components you want to accept and consume, regardless of their business dealings. Nobody gets bent out of shape when somebody picks off the pineapple from a Hawaiian, going on about implicit social contracts, but picking out the goat turds from the web content you access is some sort of immoral act by evil content thieves.
I say what we are seeing with adblock is in some sense analogous to the change in business model that the record industry was forced kicking and screaming into the digital age. websites, still adhering to the idea that they can make money for ads, throw up full-page banners, make contracts with shady advertising companies who track users across the web. So users block it. Then they throw a fit and start detecting ad blockers and throwing up pathetic "Plz disable ads" banners or even prevent you from visiting the site altogether. Eventually, it's going to become clear that Merely delivering web content through HTTP is not a business model, and needs to be part of something larger to contribute to one.