Does not getting paid matter (and how do you make it matter?).

[Vitatroll]

From my observation 90% of the time people either drop their credits, tip the entire stack, or hide them into their box to save a slot.

a minority of players will use them to buy from the debris field

I'd say that's pretty accurate. If I don't put all of mine into a machine, I'll toss it to somebody doing their job well.

People don't really value money. They value the time spent making - or using it. People weren't upset about toll booths because they lost money, - they were upset because they lost time.