A good idea
What you seem to miss is that your comment completely undermines your point. Web apps *have* failed miserably in certain respect *precisely* because they are not part of the core strengths of the Web.
Your post starts acknowledging this and then rams into a wall of bad logic. It all starts with your definition of what the "Web" is. Just like Google, you seem to define "Web" as "Browser." It doesn't matter if it is portable, or consistent across platforms, or distributed, or completely open; as long as it executes within a browser it is "Web."