IMHO, just another mindkilled person. Similar in behavior to those who pull fire alarms when their opponents try to have a debate. Except that LW is the place they want to "protect", and downvoting is the closest local equivalent of the fire alarm.

Many parts of a civilized society are built on the assumption that people in general follow some norms. For example we can only have windows because there is a norm against throwing stones into them. Once in a while someone violates the norm, but as long as they are a small minority, the problem can be dealt with. However, if suddenly half of the population would start throwing stones into windows at every opportunity, we couldn't have windows anymore, at least not how we have them now.

For a mindkilled person it is easy to believe that the usual norms don't apply to them, because the victory of their tribe is of the utmost importance.