Yes, Ruby is a "good" language but how many people are able to host ruby projects?
Ruby is a quick application to develop with and they needed to develop quickly. Usually, there are hundreds of particular aspects of a software production process that an outsider could question but just usually the tradeoffs can't be as easily made calculated from the outside as one would think.
I think the OP's idea of completely distributed servers might be as good any IF these weren't website servers but information caches akin to Freenet nodes. Freenet at least does work on some level. http://en.wikipedia.org/wiki/Freenet
