Behind the need for compensation legislation is the dirty secret of today's airline business - the reverse lottery of "disruption cost transfer" that produces thousands of tiny winners but a few big losers.
Air travel is vulnerable to much disruption entirely outside any airline's immediate control - weather, air traffic, airport problems, technical failures and politics. Statistics predict that all these WILL occur, but not in detail. On average, a particular airport might have thick fog 10 days a year - but no-one can say which dates, let alone between what hours.
In the "good old days" which some us will remember, our airlines took responsibility for their passengers from reservation to eventual arrival - routinely dealing with such disruption. They had reserve aircraft and crews, and paid for the development of fog landing facilities, just for those few days. But that meant "low efficiency", and these "unproductive" resources on standby meant higher fares for all passengers.
Now passengers are driven primarily by lower fares. Airlines know disruption WILL occur, but have cut costs and fares by dumping the practical problems and cost of dealing with it on the passengers directly affected. "Disruption cost transfer" means airlines can fly to airports which charge less - because they didn't install bad weather facilities. When it's foggy, the airline might cancel flights and refund the fare while leaving stranded passengers to solve the resulting problems for themselves. Services essential to the passenger like delivering baggage after an aircraft lands can be subcontracted to the lowest bidder, with the airline denying responsibility for the misery when things go wrong.
Hence the inverted lottery. The vast majority of passengers are relatively happy, because most of the time things go smoothly and they paid less. But those lower fares mean that when disruption DOES occur a small number of lottery losers will pick up the cost, with an expensive nightmare trip. Be careful what you wish for.....