Except as many have pointed out, it's pointless. If people used it as it should be, then those who have useful posts would have a higher number, and those who have useless posts have a lower number. Instead, those who are well-liked tend to get a higher number, and those who aren't have a lower number - both regardless of the content of their posts.
Interestingly, I was around 30-something before, and someone(s) bombed it down to almost nothing. Came back up to 10 until I just told a few people to FOAD this week. As you can see, I care an awful lot.