What I think isn't being mentioned enough in discussions about southwest is where policies of two free bags and no assigned seats fit in Southwest's business model, not just their brand identity.
Dan mentioned it in his article
Who was asking for it?
...
The gate agents? ... And the ones that will have to figure out how to board a plane under even more aggressive turnaround times than before, all while losing the time advantage of open seat assignments and low carry-on usage.
The main point of no bag fees (which means less carry-ons) and no assigned seats (which has always proven to be the fastest and boarding system) was for faster and smoother turnarounds. Efficient turnarounds means you can run a tight schedule. Which fits an airline with a "deep" map instead of a "wide" one, meaning less routes, but many more flights per route.
Couple that with using only one airplane style (Boeing 737 variants) and you can run a more uncomplicated and consistent airline, with things like scheduling crews and maintenance being more simple. As opposed to say AA with its massive route map, and massively inconsistent experience (think American eagle on a tiny regional vs Intercontinental widebody) and its many tiers of pilot and fa qualification. (That might be the reason the 737max grounding had such a devastating impact on AA but not so much SW, even though SW had more of them)
No assigned seats also meant equipment changes were easier.
You go to a purpose-built Southwest terminal, like in DAL, HOU, or their terminal at DEN, and you see similar ideas. A focus on efficiency and convenience instead of "luxury."
In short, the brand identity is one thing, but the changes to its operations and therefore business model is imho the bigger story.
This leaves spirit airlines as the only US airline with a clear vision
