You are assuming that JS+DUM can handle every new requirement and that SCGUI can't. This assumption has not been verified.And you are asserting that DOM/JS cannot handle any requirement, despite the fact that I used them to easily do exactly the same sorts of things you claim that SCGUI is required to do.
So we stick with the gummy mix of multiple protocols and crashing JS that has ended up in current browsers, or do we look at remote biz GUI requirements and make something optimized for them instead of the overly-bent HTML-dirived protocols?
Or do we perhaps do some actual design and architecture using the currently available, proven tools, and actually create a usable solution instead of attempting to (once again) rewrite the wheel?
You: "Fortran + Cobol are good enough and in common use, why move on?"
One word: XBASE.
Don't throw stones, unless you've already located a good real estate agent to find a new glass house.
Change is only good when there is a need. Fortran and Cobol have serious limitations in certain areas. You have not demonstrated that DOM/JS has the limitations you claim to be surmounting with SCGUI.