I can't be too upset at Nix. It was never his choice to be a degenerate; that is a result of his upbringing, of which he had no control over. He is a child, a product, of the internet. He is representative of a new age of individuals with no manners, no common-sense and no decency because they simply aren't given enough real human contact to know better. Nix is a lost cause, so the best I can do is not nominate him for this prize; it'd be like getting angry at a pet cane toad for existing.
Grimlock is like a three year old in a 20 year old's suit. He uses words he doesn't understand (such as "autistic", which usually applies more to him than his target), he gets all upset and in a hissy when things to apply to his specific worldview, and he connects with the garbage of the forums because anybody actually genuine here has already discredited him. He posts pictures of himself and others, probably acquaintances not trying to make an awkward social scene, all in the hope that he can convince himself that he isn't the lonely, angry piece of stuff that he actually is.
Grimlock is different to Nix in that Grimlock clearly has the means and resources to learn how to socialise with people better, yet goes out of his way to ignore these lessons so he can continue to "troll" his way around. My personal favourite example is how he posts McJob Edits™ he didn't make and then gets upset when I have no reaction, not understanding that I was the person who distributed the raw images originally and I approve of them. In his view, he doesn't get how this action he is performing with intent to make me angry isn't actually making me angry (which, if I recall, not understanding basic social interactions is a problem autistic people suffer right?), and it speaks volumes for the rest of his persona.
Grimlock is, without a shed of a doubt, the single most useless user on the entire forums. Even Lord Tony (who I frequently get upset with over his blatant bullstuff) has more value than Grimlock. Go through Tiny G's history and point out a single post that actually contributed value the topic at hand, I dare you. It doesn't count if it was in drama, especially a drama initiated by him or the people he surrounds himself with.
Just like Nix, I honestly don't think he'll ever change, but in this case specifically it's because Grimlock is purposefully ignorant. He sticks his thumbs in his ears and shouts loud sounds until anybody with a rational argument disappears. He sets a new standard for the Blockland Forum Village Idiots, and I'm sure he's a welcome addition.