The question asked was "Allow United to access your location even when you are not using the app?”. It's not clear that answering "no" would prevent the app from accessing location when you are using the app.

That's probably something a software developer / tech inclined person would know. Then again, they might assume the app is clever enough to roughly geo-locate you via IP address, and it would kinda make sense as even just knowing the town or state someone is in significantly narrows down the likely list of airports.

But even that uncertainty aside, tech folk are not the primary target audience for this app. The general flying public are. I'm not sure all of this would be immediately obvious to them. And hitting yes to a dialog that sounds as if it's asking for permission to track your every movement sounds kinda scary to me...

The point is that he didn't have an incentive to approve such wide permissions at that point. They should have waited to ask permissions until that screen, or given more information as to why you should approve their request.

On iOS it's also pretty cumbersome to allow these things after disallowing them. You have to go into settings, find the privacy tab, go to the correct requirement and then find the app to toggle it on.

I agree it's not clear from this article alone, but I've read his previous publications and it comes up a lot.

Usually that feature is to give flexible airport options. So if you search for SFO it will also give you OAK. Nothing to do with your current location.