Google didn’t respect user wishes before the flag.

DNT by default is the correct behavior because it is desired by most users. When you’re designing software and you have options for a white background or black background and 75% of your users prefer black then that should be the default, everything else remaining equal.

Tracking is definitely an “opt in” behavior, not “opt out.”

This is just Google being dishonest. Although pretty minimal since they track and always say this dumb stuff how people want “personalized ads.” They know it’s not true, but it’s sort of a white lie and we get awesome, usually, functionality.