How many regularly practicing gamemasters are there in the world? One hundred thousand? More, Less?
I use metaphor a lot to understand and learn. I keep trying to find a metaphor for what a DM does, is it like being a chef? Like being a DJ in a club? Sort of for both, but not quite either. Seems a rare hobby indeed, we have here.
One last thought. I keep hearing this idea that rules complexity is added to roleplaying games to help counteract "bad" DMs. I'm not sure if anyone believes that, but I think it is fallacious. Say for example that a "bad" DM (whether that means new, unskilled, or just a jackass, I'm not sure) needs help describing and bringing combats to life. So, someone adds more rules to combat: hit location charts, critical charts, action points, etc. And combat becomes bogged down as the poor "bad" DM needs to keep checking all these charts. Rules complexity and explicitness do not make for a better game experience by simulating an expert DM; they change the gaming experience completely.