Comparing React vs Rails is like comparing an iOS app to Rails. I don't really see the point since they are fundamentally different, and whether your application should run on the client or not is a bedrock decision long before you get to "React vs Rails". Rails isn't even an option in one of the branches of that decision.

I assume you meant to instead draw a distinction between a large framework like Rails and a tiny one like Sinatra. And I'd say that ranges from a matter of taste to the composition of your team more than anything else. Obviously there are upsides and downsides to any point you can mark on the continuum.

I meant that if the Ruby community had an inherent preference for Sinatra-like frameworks such that Rails had the same status as Meteor or Sails does these days, then you would get articles by developers saying how they miss Django when having to reimplement a bunch of stuff in Sinatra that you automatically get with Django.

But you're right that I made an invalid comparison to React. It's more the starting with Node and having to add a bunch of functionality that you would get out of the box in Rails, because a front-end framework like React is the preference, and lots of developers would rather write isomorphic apps/sites.