Totally agree regarding semantics and the problem of too much syntactic sugar.

Where JS wins for me, is that you can quickly create something that you can click on and have it do something. From a teaching perspective that kind of interaction and quick feedback is very empowering for students. This experience will quickly inspire students to think "what else can I make this thing do". I appreciate this is not the traditional CS approach, but making things fun for students is key to getting them started coding.