I go to great lengths to avoid advertising. I've even routed mail to my post office's general delivery rather than give away my address.
But I am also practical. The CEO makes a fair point that ads aren't going away. This wouldn't work as an opt-in.
The big miss here was messaging. The CEO has got to know most FF users use FF to for privacy. If they wanna make it an opt out, fine. But then people have to know there is something to out of. Then again, maybe this was in the release notes and on the blog.