"Weather" covers a lot of sins. You will find that a lot of what gets called (and allowed to be called by the FAA/DOT) "weather" is, as you point out, not really weather, but operational choices.
When a storm hits a city, yes, the first plane that had to wait to take off from the airport can be said to be delayed by weather. Every other plane waiting in line behind that plane, delayed, or because they weren't able to get to that city from other destinations because they run an overly tight schedule, is due to operational choices by the airline.
Some airlines have hubs in places where snow is handled ok. Some don't. Others have them in places that have frequent thunderstorms. Some airlines operate in Hawaii and never have delays.
JetBlue used to fly A321s across the country and in the winter, strong winds would force them to stop in Kansas to refuel. That's "weather" but also the airline's choices about how to operate.
I don't think you'll ever find the FAA/DOT is going to "root cause" what weather means to airlines to be able to blame them for operational / strategic choices. It would be like the police writing up your car accident report and saying that the reason you had a fender bender was because you chose to live so far away from work.
Thus, choose your airlines and roll your dice accordingly for when you want to get where you want to be.
Another example that bit me, flying from east coast to west coast. Storm in the Midwest we can easily avoid but that requires changing the route. Time to change the route with ATC + slightly longer flight time made the pilot time out, flight is cancelled and it’s the last of the night. AA refused to cover anyone’s accommodations because the problem was “weather”
I generally agree, but on the other hand I think the situation here presents a clear case where you could draw the line - if your airline is canceling at a rate that's, let's say, double the national average, you no longer get to claim weather.
It's difficult to punish the kind of individual cases you're describing, but from a game theory perspective that just means that in situations like today's, you bring down the hammer in incredibly punitive fashion in order to make a single systemwide failure like this so costly that it's a no-brainer to upgrade software and keep slack in the system (particularly at high-traffic, high-importance times like the holidays).
When a storm hits a city, yes, the first plane that had to wait to take off from the airport can be said to be delayed by weather. Every other plane waiting in line behind that plane, delayed, or because they weren't able to get to that city from other destinations because they run an overly tight schedule, is due to operational choices by the airline.
Some airlines have hubs in places where snow is handled ok. Some don't. Others have them in places that have frequent thunderstorms. Some airlines operate in Hawaii and never have delays.
JetBlue used to fly A321s across the country and in the winter, strong winds would force them to stop in Kansas to refuel. That's "weather" but also the airline's choices about how to operate.
I don't think you'll ever find the FAA/DOT is going to "root cause" what weather means to airlines to be able to blame them for operational / strategic choices. It would be like the police writing up your car accident report and saying that the reason you had a fender bender was because you chose to live so far away from work.
Thus, choose your airlines and roll your dice accordingly for when you want to get where you want to be.