While I agree, I'd go further and say the issue is not language as much as it is ecosystem. The ecosystems are changing more rapidly than they were 20 years ago. Or, at least, we learn about more of these changes faster than we did.

Ruby is Ruby, but do you use webrick? mongrel? thin? unicorn? passenger? Whoops! You chose what?! everyone knows that hasn't been supported for 6 months when the guy writing it quit supporting it because someone insulted him on a mailing list!

The stuff around a language is generally what changes more often than the language, and keeping up can be a challenge, regardless of age.