You can do anything in Rails/Django and some "sprinkled" JavaScript! The question is how many lines of code it will take you. The whole premise of Meteor is to

You can do anything in Rails/Django and some "sprinkled" JavaScript! The question is how many lines of code it will take you. The whole premise of Meteor is to give developers some fairly powerful features (reactivity, latency compensation, realtime syncing) with minimal lines of code. You can write these things with any other frameworks (or wire together libraries): the problem is in the writing/wiring part. You're also ignoring the fact that Meteor has only been around for something like 2 years? Rails has been around for 9! Don't make the mistake of conflating inherent problem with problems that can be mitigated with more work. To give you an example, server-side rendering is on the roadmap for Meteor. Let's also ignore for a moment that "sprinkled" JavaScript is just euphemism for writing your own little scripts with jQuery and praying they don't need to be expanded to do more things.