im not so sure if js is the right choice for beginning developers. i actually would not encourage beginning developers to jump into javascript. well, im assuming we are talking full stack here and not just client side, as the state of js is in flux and the js fatigue is real. and i cant imagine letting beginning developers to go through that even when experienced devs are having trouble dealing with it.
basically nodejs is not just getting into express anymore. although optional, most likely you will soon have to get into things like react, flux, transpiling, and understanding immutable and fuctional programming, which are all IMO a bit too much for developers to jump in to. also, js is currently changing at a rapid pace, what they learned a year ago is most likely obsolete in todays standards, ie: es5/6/7/next. i have not seen a language change so many times in such a short period of time, i cant imagine how beginning developers can deal with it.
i actually had a chat with recently grad bootcampers who went through a 3months courses of rails and then nodejs/react from General Assembly in LA. their responses to rails was easy to learn and they picked it up right away. but once they got to react/nodejs their experiences were something closer to horror.
id say js indeed was a good choice for beginners 3 - 4 years ago but now there are so many baggages involved such as dealing with setting it up through webpack and its many ways to transpile such as esnext/jade/stylus/etc.
so unless you have a few years of programming experience, i would not recommend devs to go through js at this time.
basically i can teach someone rails on how to build real world applications in a few weeks. but with js, id still be explaining the internals like what is a promise, async vs synchronous function, etc. and this even before diving into the world of redux, map reducers, webpack, immutablejs, higher order functions, and ... the list goes on.
anyway you take it, its a long road ahead with js, much longer than most people will tell you.