We attempt to walk a fine line between the power of capitalism and the rights of labor to take advantage of all that they earn. This is really hard with basic, half-way capitalism. But in Hypercatallaxy, the prefs and natural money systems help restore the laborer in a way that keeps the economy running.
The prefs you earn are yours. You cannot sell them or pass them off to someone else. You should not put them up as collateral for a loan because they cannot be transferred. You should think of them as your right to vote. It is illegal to sell your vote and you can't give it someone else.
Why? Your prefs will become your social security. If the industry you work in becomes obsolete, your pref payment stream will keep food on the table while you train for a new career.