If you're going to block their advertisements or otherwise transform their work, I'm not going to have a temper tantrum. Doing so seems objectively unethical, but in an "epsilon from jaywalking" sense, plus or minus. Even I block Flash.
There is no Board of Governors that decides what is or isn't "cheating" when it comes to laying out pages for advertising. The ethical response to a site that crosses the line isn't "now I get all your stuff with no ads". It's "now I'm not going to visit your site anymore."
Getting self-righteous about the reader's "right" to block advertising seems myopic. Yes, even when the advertising is unbelievably annoying. You can't have this one both ways. You're always going to be able to block ads, but you're not going to get to claim to be taking the high road when you do so.