JS(ES5) runs across a wider range of devices than Ruby. If the core premise is to build a single framework to consolidate all development JS(ES5) is a better r

JS(ES5) runs across a wider range of devices than Ruby. If the core premise is to build a single framework to consolidate all development JS(ES5) is a better run-time to target. One can argue that Ruby is prettier, but JS can be very good with thoughtful api design.