I always thought the selling point of Pure Python was that you might be running on some esoteric implementation of python, or hardware that the library maintainer didn't include binaries for.

I mean, I am glad wheels exist, they make things a lot easier for a lot of people. I just believed in the dream of targeting the language for maximum compatibility and hoping a better implementation would eventually run it faster.

Indeed. I was an early adopter of Google's App Engine using Python and at that time Pure Python is a must.