It's not really a Yes Track if it's simply absent. The user hasn't requested to be tracked. I'm not even sure with it set to 0 that you can assume that intent. I guess it would depend on the browsers behavior, but as you say the law is not compatible with that use.
> I'm not even sure with it set to 0 that you can assume that intent.
That's the problem. Someone not paying attention might inadvertently set DNT: 0, which is why the law is written the way it is. But at the same time we have techies who knowingly and carefully set such values and want the service to acknowledge it, contrary to the law. Hence the contention.
Granted, you can't legally use it like that where EU laws apply, per the GDPR. Hence the complaints about the GDPR you see in other comments.