>One reason the "passion tax" is possible for employers is that there seems to be a degree of labor monopsony for the kind of development done by AAA game studios.

How is the existence of a monopsony necessary or even related to a passion tax existing? Suppose the market were a fully free market with tons of software companies on one side and tons of developers on the other. It would fly in the face of reason, and fairness in my eyes, if all developers were paid the same but some got to work on fun stuff like games and others worked on the scheduling software for the scheduling software for the warehouse robot repairs. So a passion tax seems like something that should exist and not really be decried.