2. It needs to work offline, and for me to support that, I would have to double up on work, and maintaining two levels of templating.
3. No framework has made this easy, in fact new frameworks seem hell bent on making it even harder. See http://bone.io
4. Telling us to "do that." is not going to make it happen. It has to be easier, and clearly it is not: Otherwise more developers would be doing it. I want someone to convince me, but I have yet to see a post going in depth on the technical implementation of such a solution (- that adheres to the 3 points mentioned above).
5. Document-oriented sites (blogs, wikis, maybe even forums) should never have been implemented with only JS in mind anyway.