+1 to that question
It's true that we're heavier on the XAML/C# samples. There are a log of strong cases for using the power of XAML and C# and building a glossy, native app that takes advantage of numerous platform functionalities is one of them. Especially when you're more experienced with C#.
Its certainly good to know that I will be able to do the same for Windows 10 UWP apps as well. However reality is that at this point, there is very minimal information/training available to do so. For example, MVA has a whole course of building Windows 10 Universal Apps using c#/XAML (https://mva.microsoft.com/training-courses/a-developers-guide-to-windows-10) but there is no equivalent course using JS/HTML. All recent conferences (Build/TechEd/Connect etc) that I followed has sessions on creating Windows 10 USP Apps using C#/XAML but I couldn't find many useful sessions demonstrating use of JS/HTML for this.
So in theory, as you said HTML/JS could be a supported scenario in Windows 10 UWP apps, however, there aren't many evidences that MS is supporting the developer community who is keen on learning and building UWP apps us JS/HTML.
As time permits, I will be working to get video and other content in place, and will push your feedback (which I concur with strongly) up the chain. Thank you somuch for your input.