Earlier quoted context omitted.
This person's phrasing of his / her sentiment is a tad off-putting, which is why I imagine people are downvoting, but honestly I see it as the same way: I made a TCP request and fetched your data. How my data display device (i.e. web browser) displays it is up to me. If I choose to alter it or enhance it, that's up to me. It was your decision to send me your data, not to tell me how to display it.
This assumes that there is no implicit or explicit agreement between you and the content host. What if the site's TOS made you explicitly agree not to block ads (not in a hidden legalese way but with clear UX)? Would that change your calculus? What if the site owner was a friend of yours, and asked you personally not to block ads? Would that?
I've gone off topic, but the point is, if the ad-supported business model is failing, that's a problem for business to solve, not pleas to my "morality".