Killing a mage IS the start of the quest. Tahren ignores you until you do. Nor does killing a mage get you into the cabal.

The important point here is that regardless of how you view anything, everything either makes it more or less likely that a player will roll another character.

Thinking about the time it takes to find a mage online and in PK when I want to play a rager makes me want to do something else.

I have a char now who waited longer to see a mage online than you spent considering this suggestion. My time is worth something, too.