I would say these approaches were still just bandages, so it makes sense they didn't catch on. GWT, for example, was a fairly nasty leaky abstraction. I don't think it removed the need to understand the rest of the stack, and it added a whole lot of its own Java inspired complexity. XHTML wasn't solving any fundamental problems either.

In an ideal world, now that the web has shifted from being a bunch of linked documents to complex applications, we'd have a development stack aimed at developing applications, with sane means of specifying UI layout and behaviour, low overhead client-server comm protocols etc.