I'd say it's working perfectly, then. Maybe it is your business that is broken.
Sorry but that is nonsense. You should respect the DNT just because you're are receiving it and so being asked not to track.
It's perfectly possible to serve content aware adverts using BATs[1] without the creepy surveillance. You don't need to track so if you're asked to stop, just stop.
It is an ineffectual and passive way to hinder tracking.
Better ways are to be more active: to reject third-party cookies, disallow sites from storing anything, uninstall Flash and such, run AdBlock Plus, run uBlock Origin and so on.
I mean, if I visit a random site which is full of non-original content and/or simple regurgitation of press releases, why should I care about its business model and ability to monetize through tracking me? Sorry, show me value from the get-go and I might come back and let you "monetize" through whitelisting or something.
No one receiving a DNT header can say we didn't know people coming to the site didn't want to be tracked because they hadn't logged in.
It doesn't mater if it's on by default. It should still be respected.
That's different job to blocking trackers or ads.
That a site is ignoring DNT is just a sign that they are run by bad actors. It's no different to logging in to a site, opting out of tracking and the site ignoring that and tracking you secretly anyway.
...or putting some dark pattern UI in front of that option so that it's hard to tell if you've opted out or not.
Their so called "Tracking Protection" is nothing more then a gimmick. It can be bypassed easily using methods other then cookies. All it did was reduce the revenue from ads because of no cookies (the legitimate way to track id's). It did an insignificant harm to Google. But it reduced the revenue from Firefox users by a huge percentage for publishers.
Firefox is losing because it favors the wrong demographics. Firefox offers nothing much exclusive to users and neither to developers. Most people using ad blockers, use Firefox on mobile.
Sad to see it the way it is. Safari did the same. But the market share is still relevant, but it is declining as well. Once it reaches a certain point, no one will bother to test for it either.
DNT was a shit show. DNT should have always required manual user intervention to be respected.
Google's interests apart from their AMP project aligns with the publishers. If we win, they win.