Khyber is a dark and dangerous place, full of flame and smoke, where ever stranger things lie dormant.
This will keep it from confusing new players and will make it simpler to play at the table, while keeping modifications easy through modules. At the very least this is how it should be in the core rules. No need to make them any more confusing than they need to be. Cutting out the fancy schmancy psychology debates that come with older edition alignments is a clearcut way of doing this.