It seems that a lot of new players are unable to figure out how to modify roads and how to move buildings around. They set down a building with no roads and when it doesn't do anything, they give up.
Also, it would be nice to not include people in neighborhoods until they reach something more than just stone age. Maybe reaching the first tech that's not in the tutorial? The reason is that the early hoods end up stuffed with inactive players. They don't PM, they don't log in, and a few days later they're eliminated leaving neighborhoods very small.