People seem to worry far too much about the extra 5 seconds they would spend to write HTML versus HAML, when it introduces so many other problems. First of all

People seem to worry far too much about the extra 5 seconds they would spend to write HTML versus HAML, when it introduces so many other problems. First of all, there's WAI-ARIA. Try fitting that into HAML or Jade and suddenly it gets a hell of a lot more complex, pretty much negating all benefits. Additionally, I find that people think too much of the DOM tree as a goal, when it's merely the way the browsers "think" of the page. HTML is for making formatted documents, not for creating some abstract tree structure. Next thing you know, people will start representing HTML as a flowchart. (P.S. - PLEASE FOR THE LOVE OF GOD DO NOT DO THIS!) Additionally, I'll openly say I don't like CoffeeScript. But that's not because of the features it adds, it's the syntax. This is also why I use LESS instead of SASS or Stylus: it took CSS and built on it, it didn't try to replace it entirely. We're so far into abstractions today that any more will actually hurt us. Back when C was abstracting Assembly, it was important to make big leaps. Now we iterate. We take what's been done and reinvent it. So in summation: Don't Reinvent The Wheel.