No handbaggage effectively means nobody can travel with a baby or young child - unless the airline provides nappies, bottles, toys and so on. Unless there's an absolute guarantee that baggage won't be lost or delayed, those people going away for a couple of weeks needing to take medication won't be able to fly. Even with a guarantee not to lose the baggae with the medication in, there's the problem of drugs needed in flight.
At a time when the industry is in crisis, the last thing that's needed is to introduce measures which are a positive disincentive to travel.