You can kill everyone in the game and still finish it. Isn't that technically the same thing as your godmode? Why isn't the player punished for killing quest givers?
Being able to finish the game if you kill everyone does not mean that it won't have any consequences and that you will be able to get and finish each and every quest. So, if you kill a merchant, you won't be able to trade with him anymore. If you kill a quest giver then his quest may be lost for you or you do not get any hints which might be useful for you for other quests - and a punishment you do not get any quest-related XPs.
Besides, nobody forces anyone here to play by anyone's rules. It is still an alpha stage and we are just discussing here any game mechanics which strike us as inefficient, unbalanced or just odd and are making suggestions. Everyone is entitled to his/her opinion and preferences. Larian might or might not read this thread and pick up some ideas which they think would be good for the game.
