Six Hammers
 

Are there any factions who hate people that worship the Six hammers? I can't think of any...

Not directly as a result of worshipping The Tribunal, but you'll find that most Cazic/Bertoxx/Inny-worshipping races will be hostile to any races that might worship The Tribunal. Chiefly for Barbarians, their relationship with the Marr Twins is all the reason evil races need.