Hi Danial,
This seems like a "chicken or egg" discussion, and I'd like to offer my $.02.
I agree that there is no sense in having the tag there if it's not going to be used, but if more sophisticated users who want to introduce less sophisticated users to the amazing concept of remarketing, our best way to do so is via API. However, that can't be done if a manual step is required first.
I sure would love if I could tell my students "hit this button and we'll automatically create a simple remarketing campaign for you". That would be a lot more effective than "We'll create a remarketing campaign for you, but first, you have to log in, then go to your shared library, then navigate to the audiences tab, then select "remarketing", then hit the button that says "start a remarketing campaign". After you've done that, come back here and we'll create a remarketing campaign for you.
Is there a reason a basic "all visitors" tag isn't auto-created for users when their account is created? It seems that there would be a lot more buy-in for remarketing if that one simple step was implemented.
--Joel McDonald
Author: Google AdWords for Dummies