You're right, it doesn't do any harm. But I think the way he's presenting it is harmful, as it's more confusing and not intended as explanation, but more as poi

You're right, it doesn't do any harm. But I think the way he's presenting it is harmful, as it's more confusing and not intended as explanation, but more as pointing out a distinction that isn't really present. He's very fervently defending a minor point of semantics, and I feel that's harmful.