Titan Quest got pirated to hell and back which pretty much put Iron Lore out of business and THQ probably didn't have anyone left to fix it. It's one of the few cases where the developer bitched about piracy and I thought it was 100% justified, people were unapologetically pirating the shit out of that game on almost every forum I frequented. It really needed a secure online component to give those people a reason to buy it. I think the combination of unproven franchise (many people DL'd to sample or whatever) and the ease with which you could play pirated MP doomed it.
Playing: Dota 2 Reborn, The Witcher 3, Super Metroid Watching: Galaxy Quest, True Detective S2, Dark Matter