Worldcon and Comic-Con are entirely different events which happen to have some fan base in common. Comparing the two, IMHO, is not useful, any more than comparing a county fair with your local supermarket.

I agree that much of the value of Worldcon is that it travels. I was surprised to run into one of my theater pals at Denvention, who told me the only con he goes to is Worldcon, because it gives him a chance to be fannish someplace different every year.

As for the Olympics, look at the improvement it made in China.