That's about what I think. They're a talking shop to keep bored people busy sitting in their weird little City Hall. The most important job of the mayor really is as head PR guy for the city and in that you'd have to be a serious curmudgeon to even think for a second that Boris isn't doing a great job. At the time of the Beijing Olympics when the flag was handed over to Boris I was working with a large company that had a huge Chinese presence, the locals couldn't stop talking about that huge blonde bear of a mayor. Quite probably the most distinctive city mayor in the world, go to most countries and they've at least heard of him unlike most forgettable mayors.
but that wasn't the idea was it? The template was to be the hands on get things done of say the Mayor of New York.