Ruby, cachet, and maturity

I was asked recently why it is that I do not use Ruby, and instead focus on development using Python and PHP for web applications.

Basically, it is because there is stuff in my fridge older than the Ruby language.

Granted, I probably need to clean out my fridge, but the Ruby language is new, and it's long term viability seems to be coupled tightly with Rails. While TurboGears (for example) is arguably less mature than Rails, it is based on a mature language which I can readily hack into a more usable state if I run into problems (which I have not, so far).