There's a lot of money in advertising.
The feasible choices are between (a) DNT, off by default, that the more responsible and regulated side of the ad industry respects or (b) DNT, on by default, that everyone ignores.
Which one is the greater good?
In other words, you're welcome to walk up to me, slap me in the face, and call me a son-of-a-bitch... but that's probably not a great start to a conversation that ends with "Would you please work with me on this?"
And no, I don't want to "work on this", I want to not be tracked by default.
Wow, that's quite some re-framing going on there, if you're casting yourself as the advertiser in that sentence. It's more like if you were regularly "borrowing" my car without permission. Do not track is a bit like the lock on the car, which obviously you can get around in 30 seconds flat. Everyone has a lock on their car, right, and it's installed by default, so by the advertisement industry's reasoning it isn't a true indication of whether I want you "borrowing" it. If you were regularly "borrowing" my car without permission, it'd be reasonable for me to walk up to you, slap you in the face, and call you a SOB, but I'd me more likely to just call the cops.
Data about me is owned by me, and other entities can process it only in strongly limited circumstances. That's the default position, by the standard of basic decency, and also in law. Stop making it sound like me demanding control over my own possessions is unreasonable.