I think it's more that the massive engineering effort that's gone into improving JS has leapfrogged it over languages like Python, Ruby & PHP in terms of performance and tooling. And since you're stuck with JS on the frontend there are some significant advantages to using it on the backend as well.
I don't think any of the current JS frameworks are as comprehensive as Rails but it's clear where the momentum is.
I don't think any of the current JS frameworks are as comprehensive as Rails but it's clear where the momentum is.