I agree that a refund is required. However, when things become automatic, it's important to ensure that the measure is followed.
At the moment, the only automatic refund provided for under the regulations is for overbooking. The compensation has to be paid automatically within the following 48 hours. But even here, there are gaps. So we always need to make sure that the measure is complied with.
Even when a refund is offered, there are other factors to take into consideration. Passengers who learn upon arriving at the airport that they are out of luck because of overbooking should, even if given a refund, quickly take further steps. If portions of the trip had to be covered by land, they will be out of pocket. A new ticket also has to be purchased. I don't know if you've looked at the price of flights recently, but it's been increasing by almost $100 a day. This means that someone who purchased a ticket at a specific price and had it cancelled, the new ticket might cost twice as much. That passenger is caught in a last minute situation at the airport, perhaps without even being able to find another flight.
That's why damages to passengers need to be taken into account. The refund is a good start, and I fully agree with it, but more than that is needed.