The problem is that they still track you. For me, this is a show stopper; I do not want Google to track me in this fashion.
Doubleclick was marginally better in this regard, because they could only track me anonymously, but Google has my name and address already, so they can easily track me from a gmail session to surfing habits, if they want. By making anonymous ads commonplace, I'd stop blocking text ads
Another concern is that advertising has a cost. We spend huge resources on advertising, and what is the gain? If sites started enforcing more rigorous rules for advertising content, like no flash, not tracking me across sites and so on, maybe I'd not be so inclined to block ads? In short; keep the ads as a business model, but adapt it to those who don't like tracking. A static image with a link in the html of the page? I would probably not bother to block it. A text paragraph, statically in the HTML, and not loaded via JS like google ads? I'd do nothing about it.