AD / Non-Tank Style Supports

I know there really aren't many if any, especially not in the traditional sense.

But a champion like Ashe, who is actually listed as support in her secondary role, don't have a great starting support item.

Say I want to play Ashe support, which while not great, certainly isn't terrible. She doesn't seem to get the right kind of love in itemization. The best thing you can get is an Avarice Blade.

Is there a reason why itemization doesn't really exist for AD poke supports? I can only think of a few who actually work in that position anyway.

Ashe, Urgot, Teemo (to some extent)