I would say looking for work with a specific programming language is premature optimization which everybody knows is the root of all evil ;-)
Seriously the language is a detail. Your boss, coworkers and work location will have more impact on your quality of life than the tech you're using ... or you're not normal ...
Tools matter. @coffeegeek is right in that language choice is more of a signal for innovation and early adoption than it is a sign of competence or exciting problems, but would you join a team using COBOL today? If not, why not?
I have lost count of the number of jobs with 6 figure paychecks I turned down because there was no scope of programming in Scala. Sometimes being comfortable with your tools is important.
Agreed, but it might also serve as a signal of an engineering organization that is open to exploring different technologies that might be better suited for the problems at hand.
It's still up to the candidate/interviewer to determine whether that choice was a wise one, or whether they're trying to ride a wave of popularity of a specific language or framework.
Seriously the language is a detail. Your boss, coworkers and work location will have more impact on your quality of life than the tech you're using ... or you're not normal ...