There are situations where you can do things without fighting but then you lost all exp.
There are places where you can push lever or move object to kill enemy and most of time you get 0 exp.
For example when you throw big stone on adventurers before catacumbs.
THis is exactly how things work in D&D. You get XP because you deal with a difficult situation not because you go around killing commoners for meager XP gain. I support this suggestion wholeheartedly.
