It helps identify good answers to a question or post. As for it not working, I go on a few other forums for non laser related stuff, and it works very well.
We also have a like system on here already, it just involves people posting "+1 14 characters" or " I agree entirely" etc, which is far more of a pain and eats up storage as it increases the post count unnecessarily where a simple "like" vote would have added a few characters into an existing post.
From the sounds of it the biggest headache for admin on here is the gallery system which costs him a fortune in storage, bandwidth (every time someone views a post with a pic or uploads one), and a major headache with maintaining it. Yep it preserves images for ever, but at what cost? That's the real elephant in the room when there are hosts such as Imgbb to which you can upload pictures entirely for free and without an account.