To the end user, the idea of being tracked sounds like being followed around by some stalker, and is about as enticing as having your home robbed. People, in general, don't understand either the bad (the extent to which web sites can build a deep profile on you) or the good (how much of the web that everyone loves is financed through targeted advertising). As such, how things are presented is tremendously important.

Imagine if it was called "Disable Ad Personalisation", or even, "Do Not Tip" where the notion of denying monetization to the web sites you use (which is what Do Not Track will do) is invoked. It would have a very different response, I think.