I think a big part of his likeability comes from the fact that, as much as he tries to act like a badass, he's about as intimidating as a pillowcase full of marshmallow peeps. If he had real guns, his militia posturing would instantly become terrifying, but he seems quite content with his airsofts. Plus, we've all known a dude (or several) like Jace. As in, wannabe tough guys who really thought that military life would be a big vidya-and-weed party, none of whom ever sobered up long enough to enlist. At the very least we've all encountered our share of internet tough guys, and Jace combines the funniest parts of all of them with the hyperactive glee of an 8-year-old playing make-believe soldier in the backyard.
On top of all of that, he's something of an inversion of the usual lolcow formula. Your average cow takes something bright and innocent - say, Pokemon or the Powerpuff Girls or your childhood in general - and puts their own perverse spin on it until it becomes dark and creepy. Jace, meanwhile, believes he lives in a frightening world of counter-terrorism and black ops and Muslim menaces, but somehow finds a way to make it all seem like the ultimate crazy stoner anecdote. In a community devoted to studying the worst the internet has to offer, he's like a ray of (somewhat racist) sunshine.
In summary: all those times you wondered what zapping to the extreme would actually look like? It looks like Jace.
