People who take the time to search out and install ad-blocking software are not interested in clicking on banner ads anyways. I can probably count on my right hand the number of times I've (purposely) clicked on ad in the 15 years I've been surfing the web. Anyone who is annoyed at the mere act of having to look at a banner ad is highly unlikely to click on one. Thus the marginal impact on ad revenue is probably low.
And, just like every discussion ever about torrenting, it doesn't make a damn bit of difference what anyone thinks about it, because the practice will continue regardless :-) Moreso for ad blockers since they are 100% legal. So might as well stop crying.