In particular, people don't like to feel they are wasting time. Walking being a "necessary" step, doesn't feel like a waste of time.

It also distributes people through the airport to avoid localized crowding.

Years ago I discovered a bit of a trick for getting through customs in Jakarta in about 5 mins (I was travelling there a lot for work). However, what I always ended up with was standing around for about 15-20 minutes for my bags to be unloaded, as even the priority baggage was rather slow off the plane.

Seems like the passengers could have solved this themselves, by just walking in circles.

Or walking on the people movers and escalators going in the opposite direction!

Except they had to spend the same amount of time walking. If presented as a choice I'd usually choose standing.

Not me. Walking feels productive, standing is boring. Same with driving - my brain would rather feel like it’s making forward progress even if the route I take is longer.

I have a cell phone to eliminate the standing is boring problem. (Before that it would have been a book)

Even if you actually would make that choice doesn’t mean that you would be happier than if the airport implemented the other option and didn’t give you the choice. That may sound counterintuitive, but there’s no particular reason to think it’s contradictory.

Even right after getting off an airplane, where you had to sit in a cramped seat for hours on end? I’d much rather take the opportunity to stretch my legs.

It's not like they tore up all of the parking/loading/unloading areas. They just moved the baggage claim to the farthest point along which everyone had to walk anyways.

That’s a slightly different example then, because that actually does save time. Parallel vs. serial.