I have to say, as a professional web developer, that I've never found that "application markup tends to be heavy in javascript", or that I've "(screwed) up the

I have to say, as a professional web developer, that I've never found that "application markup tends to be heavy in javascript", or that I've "(screwed) up the DOM". HTML isn't particularly difficult, although things like HAML might prove that doing it well without a helper abstraction is difficult. Code management (breaking things up into appropriate templates and fragments) trumps things like HAML for ease of use and clean separation every time.