Yes because no one has built real business logic in node.js. and clearly node.js is only good for piddly todo lists. I've worked with python/Django, rails, and node.js on real complex apps with huge amounts of business logic built in them. Each one had advantages and disadvantages. I will say that MEAN certainly compared very well to both type of apps once in production. I was more productive in the other two but performance and scaling were far easier on node. You like rails, that's great but if you dismiss node and other approaches that's your loss. You'll be a poorer developer for it.