Programming Languages

Hi,
A fixation on programming languages is the sign of a 2nd rate engineer/computer scientist.
When I was at Google, SVP Alan Eustace was fond of saying that Google preferred to hire generalists over specialists. The reason is that while you might have the world's SQL expert, if you gave him a Google-sized problem, he might only attack it using a relational database, rather than apply a different approach that might be better. Hence, while Google had engineers who wrote JavaScript, they weren't hired as JavaScript-only specialists, but were generalists who decided that JavaScript was the appropriate technology to apply to a particular problem.
Most high-quality organizations have a very similar approach. Even when I was hiring to fill an Erlang server position, I found that the Erlang specialists were much worse engineers than hiring a great all-rounder and having him learn Erlang (or whatever) to fill the position.
Replace SQL/Javascript above with Java/Clojure/Scala/Fad Language of the day, and you'll understand why focusing on a specific language/technology doesn't just narrow your job prospects, it makes you look like a much worse engineer to your future employers.
Hope it helps. Please feel free to revert.
Wish You Luck!