[qihqi]

Google has to statically link everything to produce a big binary with almost no dependency (besides syscalls), because it cannot promise the environment of the server, as you might get different boxes between deployments. So, it links all the jars and jvm into a huge binary, it's a pain to deal with that because it takes minutes to build and see your change.

And still, Java is almost used for front end only. When memory is not enough, you have to use C++.