I don't think it's poorly done, so much as it isn't what you expected it to be. The text below the image pretty clearly explains the effect that you're seeing:

I don't think it's poorly done, so much as it isn't what you expected it to be. The text below the image pretty clearly explains the effect that you're seeing: > Commercial and industrial areas are also likely to be green on this map. The local shopping mall, an office park, a warehouse district or a factory may have their own Census Blocks. But if people don’t live there, they will be considered “uninhabited”. So it should be noted that just because a block is unoccupied, that does not mean it is undeveloped.