I am a unionized software developer in media, not games. I helped the game workers at Blizzard unionize and they all spoke of the "passion tax". 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. In this respect it's quite a bit like Hollywood film production in its heyday.
Thanks, you taught me a new concept, monopsony today, I didn't knew it got a name!