I totally agree with you. But that opinion reflects two kinds of programming that make up 75% of what I do -- either close to the metal, or comms protocol implementations. I was at PyCON 2016 when Guido was reading off the list of 3.6 new features. In a room full of many 100's of people, I was the only one (that I could hear) applauding for underscores. Guido himself was very dismissive of the feature and it was clear he thought it pointless, but OTOH harmless so why not let it in.

I suspect there is a strong correlation between programmers that want underscores in numeric literals, and programmers that live and breath hex.