I love being a DM but it is no mystery to me. Being a DM is a lot of work. And occasionally, a lot of annoyance. You not only have to facilitate (and sometimes create from scratch) an engaging story that keeps people coming back, you have to wrangle busy schedules and personalities that is often annoying. Lots of times you'll have a bunch of people willing to play, but no one willing to DM. So to me it's not surprising at all, and I experimented with AI in running a game, and quickly concluded it could never be good at it because it's so insanely suggestible and has poor memory.