I don't think it's that newcomers won't like Rails. I feel it just makes sense to go all Javascript instead since that's where the momentum is now and doing everything in one language has a lot of benefits especially when it's something as ubiquitous as javascript.
That wasn't what I was thinking about, there are good reasons to choose one stack over another once you are in a job. When you are job searching though there are a ton of criteria: salary, opportunities to learn and develop, autonomy in the role, enlightened management, realistic schedules, short commute, holidays, decent desk, chair and screen. I'd put all of those over a choice between Ruby and JavaScript.
