Friendly Fire is kinda a big thing in 5e
"It's kinda a big thing" in any tactical game where positioning matter. Imagine playing an XCOM where you can use explosive with complete disregard of where your men are placed during the battle.
And there's a reasons if spells that target only enemies and spells that target everyone in a given area are balanced differently, since it's an explicit trade-off.
It's always vague baffling to see people who want to play tactical games with FF disabled, frankly.
