As I understand it, the issue isn't the leftover meter money at all; it's just access to the spot. There are no meters (or there's a meter and it's trivially cheap) but there's a chronic shortage of parking spaces. So by occupying one, you claim it. That opens up the market for buying and selling spots, where the only good changing hands is the "right" to put a vehicle in a particular box of space.

Fair enough, I considered that after I left the comment and you're probably right, access to the space is probably more valuable than what's left on the meter.

Sure they will. The whole point is paying for an empty spot. Who cares if there's 20 minutes left on the meter?