Also remember Stroustrop's Law: "There are two types of programming languages. Those that nobody likes, and those that nobody uses."

To my eye Java gets a lot more usage, particularly outside of a single company's ecosystem. Some of that is because of company cultures, like Eric mentioned. Microsoft is all about increasing the value of their platform, while Sun's DNA is about open software systems and ecosystems. But the consequence is that Java is used in a lot of places that are not directly aligned with Sun's software stack or corporate vision, and it grew faster, and had more cooks in the kitchen, and as a result the overall platform is significantly less cohesive.