Let me explain why.
First the game have absolute no counter against people killing anybody normal
It would balance out in other games by make them hostile to anyone and ending up death but in DoS2 it rewards the player by XP's, even source their is reason not to.
I fear i would kill anybody on fort joy just becase it gives me to much befits from the deaths of them.
Second alignment also adds depth ingame if for example you are Lawful good and your companion is chaotic evil those 2 would clash eventually.
Also a system like faith can be added by alignment
This would be a really nice addition for a DLC or something.