Choosing "cheap" as your brand modus operandi only works if you have long term sustainable advantage on costs. They were price takers on fuel and the airports themselves don't lower gating fees just because "I'm the cheap brand". Too many uncontrollable costs...just a matter of time. And flying is a luxury service (even at those ridiculous prices) for their consumer base; it's not like consumer confidence is at an all time high this year. Higher costs, lower consumption, and rather tough inflation to swallow the past decade, and it all added up to a dying quail.
Personally, I only flew Spirit once (someone else booked the tickets, so I had no choice). It was something I wouldn't repeat, or recommend.
Their clientele was interesting to say the least. I hated having to share space with the people on Spirit; there's a bit of decorum needed in an airport to make the experience tolerable. Spirit clientele didn't help. If they had their own terminal, I could have lived with all that.
As one person said above: "The waffle house of the sky". So true.
