I think you are conflating two problems - setting to off by default is also setting a default user preference - that the user wants to be tracked. This may or may not be the case - whether the default is on or off that will be the majority setting since most people don't know / dont't care enough to change it.

I think a couple other posters here have pointed out the larger problem - without ads like this, the free internet dries up and suddenly you need to start paying for everything from gmail to facebook (or whatever other tools/blogs/webcomics any of us visit).