yeah, it's everywhere in the older game/literature/manga/etc, and then devs started to shrink back the freedom so you don't accidentally break the game logic by killing key NPC or have to make said NPC invincible. Modern day mob/field boss "quit" if you leave their area is just that you can't cheese the game or break it. So DD2 devs are gonna have a nice field trip what players can do when you give them freedom to manipulate the dumb AIs.
Morrowind handled it best. Just let whatever happens happen with zero forewarning, and if something goes awry, give the player a popup window notifying them that their save file just got ruined:
This would still be a pretty decent improvement from the first game. The tech was pretty old, towns were mostly in different instances that prevented monsters from entering, though you’d occasionally have a quest that allowed attacks inside towns. Pretty much every friendly NPC that wasn’t a pawn was woefully under-equipped for dealing with creatures that weren’t goblins or wolves. Additionally, enemies were typically isolated in certain areas, at least until endgame. If creatures are roaming and creating out-of-the-ordinary events, I say more power to them, regardless of the comparison to other newer games.