Unless microtransactions for content take off, and they haven't, ad tech is necessary to incentivize content on the web. 90% of the websites you read could not exist without the ecosystem that appnexus is a big player in. Hacker News, being one big ad for ycombinator, doesn't need to bother.
So he's doing a real thing that provides real value to the web. And it's actually a sustainable business, to boot.
Lastly, there's absolutely no need to get so personal -- if his article offended you, discuss the article.