Morally, blocking ads is equivalent of having your butler cut the ads out of the newspaper before handing it to you.
I don’t know how many of you people remember the Internet around 2000. People actually paid to be able to publish their stuff on the Internet. Because they wanted to. Without any intent on getting revenue. Unthinkable, I know!
It's the same.
The free ones they hand out in subways contain 80% ads. If you cut the ads out you will have nothing left to hold onto.
Theft requires the action to not be voluntary, but a web server replying with a page is free to reject my request. It is entirely moral.
My mp3 player will play that song you downloaded as well.
It's like your butler downloading a torrent with a song played to you.
I won't argue pirating is not moral. But it has the same morality as blocking ads.