Because? Because it's slow? Or because it's weakly typed? See it that way: Everyone and their todler can program in js, including experts of PHP, Java, Nodejs. With thousands devs, we'd see an explosion of apps, and many good quality ones in the marketplace. If there's a way we can embed V8 at an X Server level, open all OS APIs to js, sandbox while still optimizing the RAM resources, assist with the type-checking, the benefits would be huge.