Comment by ulrikrasmussen

Mozilla can have this position (and probably have it due to most of their funding coming from an ad company), but can still hold the position that the user must remain in control and be able to remove ads if they wish, even if it goes against the beliefs of Mozilla. Meanwhile, Google is actively working to make it harder to block ads in Chrome and in general work on technology which take away users freedom to control how their own computers should behave.