It is economically beneficial on a per unit basis to have things clustered. Oddly of the things I forgot to mention under services are transit and schools. Ironic in that I spend a lot of time playing devils advocate on both of these subjects.

In general I do agree that clustering makes sense in order to provide services, but lets not kid ourselves and think that actual costs will go down. Per unit costs will, but providing services ain't cheap. Collectively, 10 houses will use a lot of water and make a lot of garbage.