This is an interesting point. But if the regular travel to and from the bedroom communities is a cleaner, safer alternative to the near constant-rush-hour traffic that is possible in larger US cities ... couldn't that make the bedroom community development plan sustainable and economically available to the workforce?

Well, if you look at planning history, over and over again people have tried to get people to live somewhere they don't work. The Garden City movement of the 20s. The massive suburbanization of the postwar era. The satellite cities. They may not have the same mode of transport (respectively steam trains, cars and metro / lightrail) but their goal is always to reduce demand for the big cities and increase a cities workforce.

The problem is that these cities are defined by transportation, defined by the big city. They are completely useless as a city. All the cool stuff is in the main city, anyway, and since it's easily accessible, why bother making the suburb / sattelite a good city?

So yes, it might be good from an economic and ecological standpoint but as a community or from a societal standpoint, these kinds of developments have failed most of the time. There are exceptions, though, like Houten, which is absolutely amazing.