Because he talks about more than just this browser extension. Spoilers, I read to the end:

My personal stream was my RSS feed, you want me to replace it with a Google+ profile. My news aggregator was the RSS aggregator of my choice, you want me to use a semi-read-only version called Google+. My browser would auto-discover the stream related to any page I visited and would allow me to subscribe to it, now you want me to use a Google+ chrome plugin which in addition kills my privacy.

Everyting worked quite well, and you could pick our side and help us make it better -that’s what you’d do back in the “don’t be evil” days.

Oh, right, I forgot: You killed RSS auto-discovery in chrome, Google reader is dead, and Feedburner is a living dead. I get it.