I feel like PG has neglected the literature with this one. The two axis are probably aligned with exisiting traits from the field of psychology (agreeableness seems relevant for starters). It's nice that he considered all this, but I think he did so in his own bubble.

There can be benefits from reinventing things in your own way, but to completely overlook the existing work can be a mistake too. There is so much more out there on this stuff than analogies from junior high.