Because he's an actual troll. I don't care how deaf he is, that's no excuse for having such piss poor communication skills, especially in typing where the words and everything is shown right in your face.
Tbh I've always wondered if Furling has some other condition that forgets up his communication skills. I mean, I've seen that sort of thing once every now and then.
The thing with trolls is they usually drop the act every now and again. Furling hasn't stopped talking like this once, and he types fast enough that it's obvious he's not stopping to word his stuff like this.