As I see it, the difference is that some people for whatever reason won't write a sentence to thank the poster but will post a +1 or click a button. I would like a button to replace those content-free +1 posts, not the full sentence replies which I agree are valuable.
The content free "+<insert number here>" posts will not go away via having a like/enhancement button-reporting the post to the forum's moderators will make the "content-free" posts go away