They know it’s dehumanizing. They know it’s an insult.

It’s just one the mods will tolerate, so they use it. Treat them with the same courtesy and you may be banned (depending on the mod’s inclination).

They pretend to not insult you deliberately, and pretend not to comprehend the most basic of points.

So, it’s best to treat them with baby gloves and keep things very simple secure in the knowledge that they will never, ever concede a point or admit that they’re wrong. Use them to refine your arguments for real thinking people.