If the ads are presented in a nice way (no animated flash popups with sound (or any subset)), are for something good and not delivered through a data-mining ad network, I don't mind. Those will often get through my ad blocking filters all by themselves.
But the ads only pay if people click on them. I don't click on ads, EVER. I never have, and have never even been close to. Some people do click them, obviously. Since I'm not clicking them, anyway - me using an ad blocker only saves the advertiser bandwidth money.
I have only clicked an ad once in my life. I was searching Amazon but couldn't find anything suitable. Then I noticed they were showing me an ad from a 3rd-party site for exactly what I was looking for. I clicked it, and bought the product. So at this rate, ads help me out about once every 15 years.
I explicitly said "there are people that click on those ads". Those people don't have Ad Blockers. I don't click on those ads, so I have an Ad Blocker. All I was saying was that it doesn't present an ethical problem.