This isn't just about C++ versus Java - think platforms.
In my company, we have some high-volume, robust, scalable and secure web applications which simply cannot be developed without an industrial
J2EE server (we use WebLogic Server), so our primary development language is Java. This server also provides a bunch of services like failover and scalability. If you need an application server which does the kind of things that WebLogic Server provides, then you'd better be a Java developer.
It's possible to make a case for lots of other languages like C++, VB, COBOL, PL/1, etc, for new applications, but very few new applications are allowed to use any of these languages. From memory, it is mandated that web applications must be written in Java but VB can be used in certain cases. There are quite a few people in my department who are supporting legacy non-Java applications, but they are unlikely to do any development unless they learn Java.