I’m sure that if the club concerned go through official channels they will be given the full details by CCC of why the fine was imposed.
Everyone is agreed that the hundreds of kids playing on the pitch at halftime is a wonderful sight, however the risk of injury is enormous to the participants and to others sitting or standing nearby. For instance no hurler will train or play nowadays without wearing a helmet yet I don’t recall ever seeing any child wearing a helmet in the mass puck around in the Nell.
Parents, in particular, have a responsibility to mind their own children and allowing small children to play on the pitch while adult men are warming up by sprinting, belting balls around etc is just inviting serious injury or worse and shows a complete disregard for health and safety.
The stewards are in a no win situation, if something happens they were wrong and if they ask people not to enter the pitch area they are usually verbally abused (sometimes physically abused) by parents who think their kids have an entitlement to play on the pitch between games or at halftime.