The only way to stop passengers evacuating with their carry-on baggage is to make them check it in. The majority of airlines now offer 'Hand-baggage only' fares so the consumer thinks he can get a better deal by carrying a smaller suitcase onboard. This behaviour is completely driven by commercial considerations and is patently to the detriment of Flight Safety.
As always the primary concern of regulators is the continued commercial success of the country's airlines. It will take another Manchester air disaster where NOBODY survives a runway evacuation before a civil-servant ends up in the dock for permitting such a commercially led situation to arise.