I reckon that those people who go "Ooooh, no, never, what if you roll on the baby, it's dangerous!" probably shouldn't do it, because they're using their own sleep patterns and habits to inform their opinions (fair enough) - and if they feel they'd sleep too deeply for it to be safe, it probably wouldn't be.
But I do wish they'd not pull faces at those of us who sleep lightly enough for it to be fine.