If I could reply to that ... straight-up-and-down and without fear (which BTW I don’t have) of “downvotes” ... my very simple reply would be this:  

“It does not help me at all,” because:

• I have no idea why you did it.   (Do you object to the content, or to the author, or are you (were you, five years ago...) just having a bad hair day?)
• If I am searching for this thread, three years hence, your “(up/down)vote” adds absolutely no semantics (tags, attributes, etc...) to the thread.

WikiPedia might be the best illustration of what might usefully be done:   a system for commenting about the content, expressed as categories that can be tabulated.   A “vote” is merely a number, unless it is paired with attributes and intended to be useful “for years to come.”