Yay! Dedicated to my French co-workers in the office :P
Seriously though, it just reflects the fact Tokyo has more restaurants (good or bad) based on the population and its density. And most of the star-rated restaurants we don't even consider going since they're still expensive.
The beauty of Tokyo life is that I can get a decent food anywhere, anytime (even 2am in the midnight) in Tokyo with the half-price of that in San Francisco.