The most important thing is that learning other languages and frameworks really helps expand your perspective. It's fascinating and fun to learn how another framework in a different language solves common problems like security, routing, or UI abstractions.

Any time you see a problem approached from a new angle, it deepens your understanding of that domain. You learn what patterns are common and what tradeoffs are made.

I gueninely believe learning Python or Erlang makes you a better Ruby programmer. You don't have to cross over to reap the benefits.