A lot of web development curriculum these days tends to focus on writing apps with JavaScript, or learning a new library. HTML/CSS is still taught, but I feel the “HTML is not a real language” sort of drives people away.
A big difficulty is that HTML by itself doesn't give you good ways to define templates so it's a pretty dreadful task.
Web components can change that in the future but until that it's pretty normal for developers to opt for tools that allow for creating a HTML fragment and building up HTML in another language.
Imagine if we had to do the c calling convention song and dance on every function call...
