Based on a recent experience, I'm going to disagree with this.
Back in January, I was due to fly home from California, when they cancelled my flight about an hour before I was due to check in. We were then told that there was NOTHING that would get me home for the next two days "due to weather." Umm, how did they conveniently know that my flight the next day wouldn't be able to fly just before check-in? Yes, there were storms in areas of the country, but it seems like Southwest's MO at that point was to cancel everything rather than trying to risk system-wide issues like they had around Christmas 2022. And their response to customers is "deal with it, there's nothing we can do." I know many people who flew SW around that same time (I was at DL for the runDisney weekend so there were a lot of us) and a bunch of people had similar stories.
I was in Los Angeles and I was willing to take any airport and they claimed that there was nothing available. However, I found out later that my flight from Chicago to Buffalo did fly and arrive that night on time. So all they were looking for was two seats on any flight from L.A. to Chicago.
In the end, I wound up spending double the money to fly on a non-stop JetBlue flight on my original return day. How is it that JetBlue could manage to fly (I was watching cancellations throughout their system and there just weren't many), but SW couldn't?
From now on, I won't be flying SW in the "risky" weather months or anytime when I need to be in a certain place at a certain time. Just my experience...
That's okay you're certainly able to disagree

I just wouldn't want any one person, especially newer to SWA, to base off any one person's recent experience (including my own). It's historical and long-term usage of an airline that I was discussing, especially without having codeshare agreement.
As far as your cancellation when weather hits, especially significant storms consequences from that aren't always a one day thing. They often have ripple effects that can affect for several days even. Their planes handle anywhere from 143 to 175 passengers. So shifting all (which many flights go out full or nearly full) can take time and shuffling around. This happens to all airlines where it can take days to get you on the next available flight and has most def. happened to people I know.
As far as how could JetBlue fly but not SWA? Well because you need to know where planes are coming from and going to, what is in their fleet, etc. Like I mentioned to another poster flightaware is a good place to check. I used to watch my husband flights when he was in Long Beach, CA to home, from Houston, TX to home and from Baltimore, Maryland to home when he was flying back and forth every two weeks for months and months. You get to learn the pathway of a plane. His flight from Maryland coming back home (to the middle of the U.S.) often started in California in the morning making its way across the U.S. (I believe it stopped in TX, then Nashville, then North Carolina, etc) and if any storms happened along the way it could impact his flight (and this did happen). One time there was a cancellation due to crew time outs.
People hear "weather" and think it strictly pertains to where they are at but that is not how thousands of planes are able to fly across the U.S. each day.
But on a positive note like I mentioned a bit back on this thread on our February trip from
UT back home "a baggage cart hit the plane causing a gouge in it and taking the plane out of service and the 12 or so of us on the plane had to deplane and wait in the gate area. They were able to get us a new plane quite quickly (maybe 20 or so minutes)" so they had the ability that take to take another flight's intended plane to use for ours. I can't fault any airline for not being able to that as a norm and count it as we got lucky. I sure hope the passengers whose plane we took were able to get out quickly enough otherwise they could have felt like you did with being upset with SWA.