Separation of concerns and separation of technologies are a different thing. It would appear you haven't done your research. See Pete Hunt's famous talk:
Hm.. I didn't say a word about separation of technologies. If you have one non-broken piece of HTML and related piece of JS to make it "live" - it's one thing. If you use JS/php/python/ruby/lua/whatever to generate HTML, composing it by small pieces into one (inside one component) - it's another thing and it's exactly what I'm talking about.