Maybe, we could implement the thanks button on the users profile page, because if somebody does something for somebody outside of codingforums or a post, then they could thank them on their user page.
I think that would be more appropriate for the Rep feature, since thanks are applied to specific posts, but reps are a bit more general; I've been repped for stuff like "nice site", etc, that doesn't apply to a specific post.
I think your missing it, if somebody helps you outside of a post, and don't want to give 'reputation' which doesn't really show on your posting profile, a thank can be displayed on the posting profile