If you cannot play without minmaxing is really a you thing, the fact that you can get better stuff if you kill everyone doesn't mean you HAVE to do it xD. Usually killing everything gives you more XP than defusing a fight through diplomacy but if you don't level up by milestones is hard to balance, specially if you can get xp from ability checks and then kill everyone in sight.
Again, it's just a minmaxing thing and as everything else I think that having the option to do it is always better than having no options.
Not the point. My point is that game mechanics shouldn't give you extra rewards for being extra violent. If you kill everyone, you will get their stuff. That's in the nature of the thing, and if you kill people for their loot, that's part of roleplaying. However, the game *mechanics* shouldn't give you an extra reward in form of xp, thereby basically telling you "Hey well done. Talking is for pussies".
Some games give xp only for missions. I always find that a big relief since I can then roleplay without having to wonder if I make myself extra-weak for future events by being an intelligent person and fighting only when necessary. And if I'm in the mood for an extra session of hard fighting, there are monster hunter quests or head hunting quests featuring special enemies where the killing is the objective rather than one of several means to the same end.
And that's not even touching the other two aspects I mentioned in my first post.
