Chasing Programming Fads
hyperdimensionalrabbit.blogspot.com
hyperdimensionalrabbit.blogspot.com
The requirements of the work to be done keep changing as technology grows. Ruby is dying because, right now, it makes more sense to do the work on the front end.
Even then, there's a lot that is going to end up staing on the client, for convenience. Just like Ruby isn't going to go away - it's just that delivering JSON to single page apps is an increasing portion of its job.