Java was designed to make it possible for an army of mediocre programmers to not mess up too badly and to actually produce something. That is according to Gosling himself. It is hell on earth for much better programmers. It also brought in or at least accentuated the cookie cutter coder drone model of software development and ideal teams so popular for much too long with many a software manager. They didn't want any "heroes" or any that were 10x to 100x more productive. So Java makes is nearly impossible to be that productive.
Now the "rebellion" builds clojure, scala, jruby etc. to drain this swamp.