You basically described HTTP and web browsers, but with restrictions on the type of content that can be created based on nothing more than your preferences. The market in general has spoken pretty clearly that they want more capability, so I just can't grant that you have a real point. The popularity of your concept on HN is no real surprise given the conservative bent of some techies, but it's the sort of opinion that gets no traction out in the world because it relies on retarding progress.