Here's the way I see it: people ofttimes wish to converse about the relative importance of things or actions. In fact, being able to communicate notions of preference, to explain them and argue about them (and mislead each other) is awesome ! It should be cherished and developed. Money is like a grunt or a smile or an odor one party emits, on a scale of weaker to stronger, to tell another party: I think this is only worth X; that is worth 2X and that is worth 3X...
It would be nice and helpful to be able to non-verbally "discuss" the relative values of EVERYTHING quickly and clearly, with pretty much anyone or any thing. We need a standard of measure. Somehow we unconsciously settled on using what most people would agree on as the most valuable limited resource: time.
This is worth 20 minutes of my life. I would exchange 3 days of my life for that. Can you achieve this objective in 5 weeks or 5 years? If you can do it in 5 weeks, whereas it would take me 5 years, then maybe you can do it for me and I can do something for you (that takes me less than 5 years) in exchange?
I don't care if it is gifting or whatever. Ultimately it boils down to communicating relative importance using human life, measured in time, as the yardstick. We've gotten good at that, as a society. Where we really fail is in our actual ideas about the relative importance of things and actions.