Tieflings in 5e are common and normal, but that wasn't the case when BG1, BG2, and Neverwinter Nights were made. For people that are fans of Forgotten Realms through these games, it might come off as strange that horned devil-people are just walking around, and you interact with them as if they aren't a monster. BG3 itself makes this worse by introducing you to actual devils in hell, so we've established that red-horned devils are creatures from hell. (and they look almost indistinguishable from Tieflings)
Then we run into Tieflings at the druid grove, and we just talk to them as if they are people. Narratively it makes no sense. You would rightfully think they were invaders from hell that followed your ship.
Something simple could fix this, like a few lines of dialogue. But the game should teach you the difference between Tieflings and Devils. The current arrangement where you should just know a refugee camp full devils is okay seems off and confusing.
