Or, small children annoy people with bikes, because some people try to take small children where not appropriate, and this is dangerous when small children change direction unpredictably.
Chicago Lakefront.
You're creating a hard and fast rule that X group should always be allowed, the parent was saying all groups should behave reasonably towards each other.
I think the parents view is more reasonable. You could still take the view that bikes will always be dangerous to children, at that point you can then decide whether to prioritise children or bikes.