It just seems today that good customer service is measured by the amount of FREE stuff you get!...although we SAY," I just want good costumer service", what we really mean is FREE stuff.
Spirit is no exemption, and just like a previous poster, the average "once every 6 months" passenger does not have a clue about the ticket "contract" that they purchase online at the lowest possible price.
READ, I say to them...

Complainers, do complain for just about anything, the problem with this is that shadows the person/s having legit problem/s.

This SAN incident it's a great example. Everyone inside the a/c smelled the fumes, if you have been in an a/c in the last 100 yrs more than a few times you'll know that THIS happens, not often, but it does, after refueling, during refueling, fumes taking in via the ground AC cart or pack inlets.
We know that, and even some seasonal flyers know that as well.

Spirit it isn't the only company flying airplanes, it happens everywhere, including in your car after refueling, your boat, whatever, NOT often, but it does. But in an airplane, after you paid an exorbitant amount of money, (under100) to fly over 900 miles, it's a great place to get something in return. "I want"

The actions taken by the crew were probably normal until they realized that the fumes weren't going away. MTX it's called, procedures are follow, flight cancels.

We complain, just because its today's culture,

-why other planes take off and we don't-
(LGA waiting for TO)

-My sister says the wx in ORD it's fine, why isn't the pilot going?-
(Wx delay into BOS)

-why don't we have more leg room?, I paid 59 bucks for this trip, + 45 for a bag-
(Guy going from FLL to ACY)

Every airline gets these ppl, spirit it's just an easy target, and we don't advertise all the hundred of thousands of happy people that go unnoticed every week. Because they'll come back.

Cheers.