Who knows? Perhaps DHH doesn't follow jey's instructions to install ruby and start a rails project?

In any event web services like Heroku make it a moot point. I've yet to try it out but I can easily see the attraction when a trivial google search of "ruby install error" returns 100,000 hits.

Results 1 - 10 of about 153,000 for ruby install error. (0.23 seconds)

Results 1 - 10 of about 166,000 for python install error. (0.26 seconds)

Results 1 - 10 of about 264,000 for java install error. (0.22 seconds)

Results 1 - 10 of about 145,000 for gcc install error. (0.25 seconds)

This metric seems flawed.

I'm not claiming other languages are easier to install. I'm saying there is value in offering development tools over the web in a way that eliminates any need for installation.