It's worth noting that Microsoft enabled Do Not Track in Internet Explorer by default just after it started to gain traction, which caused a small backlash against its use [0], notably Apache started to ignore all DNT headers from Internet Explorer.

I have to wonder whether it was an intentional effort by Microsoft to discredit DNT and to stop people from respecting it... On one hand, the same outcome (almost ignored everywhere) is likely to occur regardless of whether Microsoft made its move, on the other hand, it may have gave it a greater push.

[0] I have my cynical Fundamental Law of Privacy - it must not be enabled by default, so that the industry will continue profiting from it, while giving the user the illusion of choice. But at least those who enabled it enjoyed privacy, although only to a very limited extent.