Other than companies like Google most marketing companies couldn't give a shit about what you think of them as you aren't their customer. Additionally a lot of

Other than companies like Google most marketing companies couldn't give a shit about what you think of them as you aren't their customer. Additionally a lot of marketing companies would likely publicly get behind a DNT header when the recommendation is that browsers send "no preference set" by default. As soon as a browser vendor goes to default DNT the marketers support of the standard and honoring of it will go out the window as it's not in their interests to participate any longer. The end result will be that Microsofts choice will result in everyone being tracked rather than only those people that have no preference set or have explicitly opted in. A good example of companies not honoring a restrictive default is the P3P header. Damn near everyone sends a P3P header but most of them don't actually honor the settings from the header, or have the other components set up. It's all about getting third party cookies set successfully and not honoring how MS implemented P3P in IE or what the user wants.