You got it. To profitably support commercial power users I would have had to change the business model to a pay-as-you-go subscription model. I considered doing this in a way that wouldn't shut out my casual users (for whom I created the app in the first place, and who are still the majority), but I had serious doubts about the willingness of taxi and limo drivers to pay for Just Landed on an ongoing basis.

The proliferation of half-decent free flight trackers (albeit without the unique airport pickup focus), the other systemic problems mentioned in my post, and the increasingly common cannibalization of utility apps by Apple's iOS itself, led me to the conclusion that such an endeavor was likely doomed to fail.

Just because you can find passionate users doesn't mean you've found a good business, and that was the case here.

Why "500 times"?