Yeah, I also thought the on-call/pager thing was a little overblown. It immediately raised a red flag about how wet behind the ears OP is.
Not to say that there aren't toxic on-call rotations and such, only that it's a lot more common than you'd think, and is not limited to just doctors eyeroll
Any time a business unit needs to be accountable to another party after-hours, some sort of call schedule is created.