In the War Tavern only 3 topics have stories (one of which links to two off-site) with Jazz as a main character
This one happens to be about Lori's Origins.
This includes Lori, but you could just switch out the names of Jazz characters and no one would notice a thing, thats how non-connected it is.
I'm not really sure if Jazz counts as a main character here, he seems much more secondary
Jazz with some original characters
So the ratio is 1:4 if we don't factor in whether the character really is Jazz or dispute how much of a main character he is. Now let's factor in the fact that the War Tavern's front page goes back to Dec. 2005.
So all in all, I'm not exactly sure where this Anti-Jazz hate is coming from