Just heard about this today. Interesting reading the comments on github.
Without knowing the full history of Do Not Track, I don't know if I can comment (but I will do, anyway!), but the impression I've got is that having this set to True by default is better for me as a consumer. Do I really have to think long and hard about whether I want to be tracked across the web by advertisers? I see this as the same sort of thing as blocking popups by default. Like popups, I do not want to see them (as, I imagine, do the majority of people), therefore I'm happy having that set as a default setting.
I know that the argument against it is that DNT is supposed to be a 'non-default option'. And by having it set to True as default will essentially mean that the signal will be ignored by all, thus making the signal useless. There's a flaw in that thinking - just because the masses have it set to True (by default or otherwise), doesn't mean it is useless and should be ignored, but rather means that the majority of people do not wished to be tracked, and advertisers should honour that. If there is value in it being set to False for the user, then they will figure out how to change it back, or the default will be changed, but I doubt such value will be found.
It seems to me that everyone is happy with this whole DNT thing as long as it is not used by all. As long as it's only a setting that is used by the few who are really keen to protect their privacy, then everyone will go along with it. But apparently, if the majority begin to use it, then there are problems. Maybe the amount of money that is to be lost (or less money gained) by advertisers and advertising networks is starting to hit home.
My basic impression: the decision to do this at Apache is petty, and has damaged Apache's reputation. I'm happy for IE10 to set this by default. It is the option I would have set, therefore have no reason to want to explicitly set it myself. I frankly don't care what some specification says about 'how' this preference is to be set, or by whom, but at the end of the day, I do not wish to be tracked by advertisers. End of.