It may well be underpaid compared to it's difficulty level, but the jobs exist.
Meanwhile I've yet to see a Rails job that pays enough to be worth my while, despite Ruby being by far my favourite language.
I get to use Ruby a lot (rarely Rails; don't like the thing), but because I am typically in senior enough positions to have autonomy in what I choose for my projects - the moment a job is advertised as a Rails job, the pay is accordingly low.
