Where were you when WebGL, WebRTC, HTML5, etc was introduced? Did you ask "Why do we have yet another graphics api/real time communications api/video streaming api?" back then? No you didn't. The web needs solutions that are built for the web, otherwise it's not going to work.

Especially the "Why not the JVM?" questions tick me off. The people asking this question must be living under a rock. The Web already tried java applets and failed.