For a "typical" web project, Rails simply has a ton of mature libraries that don't exist in Node, or are very early days. Sure, there might be a basic data mapper, but does it have support for testing? Automatic counter caching? Workaround on StackOverflow for a hundred things the framework doesn't cover by default?
Rails versus NodeJS isn't apples-to-oranges. Rails is an opinionated framework for web development, Node is a low-level evented framework. This is important because right now, Node has no Rails equivalent. It has Express as the equivalent of Ruby's Sinatra, but for a higher-level web framework, there are several possibilities and none of them the outright leader. This is the situation Python found itself in circa 2006, before Django became the de facto standard for web apps, and (speaking as a mostly-outsider) its seems to me the Python community is better for it. I truly hope a high-level framework establishes itself as the clear standard for Node development, presumably one which embraces the benefits of dual-side JavaScript.