because Jhawk was a closet faggot and would post embarrassing things drunk, such as how his mother forced him to recite/memorize bible verses, and a thread about wanting to 'give edvard a blowy!!!'. jim is out of the closet, doesn't have to hide this part of himself, and i believed raven when she suggested he was now on drugs and act like a retard in chat all day as a result.
he's not really even trying to pretend he wasn't Jhawk, he's telling you that he can guarantee jhawk will agree with him, when he comes around - cue retarded 'jhawk' puppet supporting this. how could he have known jhawk wouldn't just troll and say that he was jim, or that he would show up? jhawk is also the only person jimmy regularly praises and says he wishes he could be more like him. that's how he works, making 'fans' like Tom (not virus) to try to give the impression he is revered by others.