First, I love ruby & rails. It jives with me. will it be around for another 10 years? there is no doubt in my mind. It has kept up with times and the contributors just keeping growing. I still love it 4 years in. There's a lot of snark at ruby & rails, but it is out of mostly jealousy & false ideologies. There's a lot of rhetoric about scaling and such that for the most part isn't true.
certainly not everyone uses rails, but i still see enough out there using it that i'm not concerned for it's future. If, given the choice of frameworks to use, people keep picking rails - it will live out quite a long life.
But you should really be the one to decide, in the end. As a language and framework, both are enjoyable and fairly straightforward. Few WTF moments (unlike my former PHP days)
is it worth learning? yes. Even a little can get you far. Node is good for things too - but not quite the same things.
but what matters more is building things. That will look awesome on your resume no matter what you build it with.