True enough That said, it's always easier to learn fundamentals (no matter how boring) at the start, rather than after you've already developed habits. Well-grounded fundamentals will not only help to prevent you from developing bad habits, but will also significantly aid your ability to pick up other languages later on, by appreciating the differences in their fundamental structure.
Very, very true - and I can see why you've made your case for JS in this case, but I still disagree that it's the most viable way to get quick results as, often, it is combined with HTML, requiring the user to understand that, and the interactions and boundaries between the two. Something like C#, for example, is relatively quick to develop with, you can get quick results (either with command-line programs *or* with a visual UI developer). "Quick results" often depends on teaching. Someone (or some document) which teaches well, will give the learner the opportunity to see results quickly.
But you still have to learn the basic principles - such as braking, accelerating, traction, understeer and oversteer... or you're just going to end up spinning off into walls all day. I'm not saying he has to go hardcore straight away, but it is important to have something that covers the fundamentals. Otherwise it's like learning how to drive the BF1 in LFS with a wheel by starting out with playing NFS on your keyboard... it's a slight resemblance, but nothing that's going to give you much benefit.
Of course, this is all just my opinion