If we dont know who liked us, or which post, .... why is it there??
I think the intention is to encourage the recognition of consistent good reviewers or people who otherwise contribute, rather than individual posts. I like the anonymity as it encourages impartiality rather than cronyism or "I scratch your back, you scratch mine".
I was once a member of the forum of a print magazine. Not only were Likes awarded on a per-post basis, but a "forum post of the month" would also be featured in the print magazine. The result, predictably, was that forumites would post in soundbites in an attempt to be noticed. It was pretty excrutiating, in hindsight.