Actually, with the magic of Windows Live Local, we can see firsthand: Why South Lake Union Will Never Look Like Stuttgart (or any similar German city).
Answer: The blocks are too small.
South Lake Union
Stuttgart
Far-away of the same area
If they consolidated blocks in South Lake Union (about every 2 or 4), they *might* be able to get the pattern you see in these pictures of Stuttgart - though they might also have to split up parcels (or write a zoning code to force developers to make single projects "look" like several smaller ones).
There could be hope for Bellevue, but alas, while Bellevue has big blocks, it also has big parcels.
To get an urban "texture" like this, you'd need big blocks, but small parcels.
Sorry for the thread diversion.