Sometimes people confuse demand for profit. Certainly, there's great demand for nonstop flights between New York City and Orlando. But, each city pair has a limit to the maximum fare an airline can charge. That limit is based in part on how many other airlines offer flights. Generally, more competition equals lower prices.
By removing flights, an airline can actually increase overall profit because they might be able to charge higher fares. They can also move that plane to a different route that is underserved.
Today, decisions about where to place planes is largely done via wildly complex computer software. Using decades worth of data, the software analyzes how eliminating a route will affect the remainder of the flights on both the nonstop city pair as well as all connecting flights into and out of the each city.
I guarantee that every Southwest competitor because analyzing their route networks using their software the instant this schedule change was announced. The other large "legacy" US carriers (American, Delta, United) all have an advantage over Southwest because they have a wider number of aircraft types. That means they can right-size flight by substituting a larger or smaller aircraft.
Narrowbody Plane Types by Airline
(Including regional partners. Note: Southwest does not have regional partners)
- American Airlines: 25 plane types; 44 to 188 seats
- Delta Airlines: 14 plane types; 50 to 234 seats
- Southwest Airlines: 3 plane types; 143 to 175 seats
- United Airlines: 30 plane types; 30 to 232 seats
Data Courtesy:
https://www.seatguru.com/browseairlines/browseairlines.php