Simple reasons really that have little to do with the terminal or airfield:
has some of the most severe seasonal fluctuations in traffic of any airport in the nation. Peak traffic levels in March and April are 2.5 to 3 times as high as traffic levels in September and October. Southwest generally doesn't do much scheduling for seasonal variation aside from an extra Saturday flight here and there due to the extra costs in equipment, staffing, gates, etc.
2. Southwest specializes in short-haul flying; however, only one WN
Florida station (JAX
) is far enough away to justify flights (though I doubt JAX
is a very popular route). TPA
, and PBI
are all too close to RSW
was discontinued because driving takes less time.
If you take away the short-haul Florida stations, it gets tough to get to 10-12 daily frequencies; I could imagine 3 to BWI
, 2 to ISP
, 2 to MDW
, 2 to MSY
, 1 to BNA
potentially, but it would be tough to fill those consistently. This roughly what PBI
gets right now, and it has more population.
3. The catchment area population is significantly smaller than what you see at FLL
, and JAX
; this is part of why the traffic is so seasonal.
It is true that there's pretty much no room for WN
at the current terminal, but I don't think gate space is truly what's keeping them out of RSW
. I imagine, though, that they MIGHT go to RSW
once they're more established at PHL
and their ISP
terminal is completed, but there are probably better opportunities in higher-fare markets right now.
As for SRQ
, it's too close to TPA
and my understanding is that the rents/landing fees there are among the highest in the country (which is not good given its traffic is primarily leisure-driven).