Possibly. Or possibly he's deciding to go after the weaker claim, or is personally too cowardly to accept the lifestyle consequences of full-on consequentialism, or you should accept at face value his arguments that even on consequentialist grounds high-paying finance jobs are likely to destroy as much as they create. I'm mostly speculating based on my experiences among the kommie krowd and what I like to imagine (though don't we all) is a developed sympathetic understanding of other tribes as well. This shouldn't be read as a strong claim or even really a claim at all about Mills specifically. (From your summary it sounds like you found yourself confused by Mills' arguments, so either it is hopelessly confused, or you might benefit from giving it another go, or there's simply too much inferential distance at this moment.)