Hussar
Legend
Fair enough I suppose. I see a significant difference between, "Sorry, no you can't play that because it would force me to rewrite large swaths of the settings and I'm not really interested in having you dump that much work in my lap" and "No, you can't play that because I don't like it."
To me, one is perfectly reasonable and makes sense. The other is the DM forcing his personal tastes on the player and it's a DMing fail.