This is quite true, the way companies hyper-concentrate is not really given much thought it seems. There are obviously benefits to concentration when it comes to fostering innovation but like everything I imagine there is a point of diminishing returns beyond which the benefits turn to negative.<p>A similar phenomenon can be seen in the DC area, all the companies are hyper-concentrated in NoVa creating a miserable commuting situation for hundreds of thousands of area residents, meanwhile a city like Baltimore a mere 40 miles away is completely ignored when it comes to locating offices.