I think the situation with web languages and technologies is vaguely like the situation with C++ in one particular way: It isn't that they're really good, it's

I think the situation with web languages and technologies is vaguely like the situation with C++ in one particular way: It isn't that they're really good, it's more that they've been around so long, evolving at glacial pace, and there is such a huge community compelled to use them, that we've collectively figured out how to make them passably effective. If I were designing a web application platform on purpose, major design criteria might be: 1) data and apps hosted remotely, 2) discoverable apps/services, 3) hypertext-style linking of resources, 4) ability to fully exploit client CPU and GPU power for UI, and for compute where appropriate, 5) consistency with common desktop UI concepts (like drag/drop), 6) flexibility in languages and developer tools, allowing for compiled, statically checked languages for those who like them. With the current web, I think we have 1-3, but not 4-6. (I think I would trade the enforced niceties of HTML/CSS for more flexibility in the UI.)