> but a key distinction here is that you are using Facebook for absolutely no out-of-pocket expenditure

Here's my perspective: I would pay for an ad-free subscription, but they don't offer one. They literally will not take the money I have to offer.

Imagine walking into Stabucks and having them refuse to take your money but instead handing you a coffee and a booklet of ads. Is it bad to throw the ads in the bin? Would the barista become angry and start shouting ads at you too? Or, more likely, ask you not to come back?

Note: I don't use Facebook on the principle that they want to commoditise me instead of taking my money, but I see nothing wrong with blocking their ads should someone not hold that principle.