Sure, the money has to come from somewhere, but, no ad server has ever managed to fully eradicate malware from the ads they serve and some sites have so much of the page covered in ads that the site simply isn't navigable without an ad blocker. The first is on the ad server companies, but the second one is just stupid. I will simply never trust ad servers anymore after having seen computers destroyed by ad-delivered malware, including one of my own. Even if the websites themselves go back to a more restrained and reasonable number of ads, I will never turn my ad blocker off for simple safety reasons.