Mailing the story:
Java, Meet Python. Python, Meet Java
Java (specifically J2EE) is good at things like dealing with large number of transactions, dealing with application state, and stuff like that. But a significant majority of applications on the Web don't necessarily generate enough of a transaction load to justify the penalties you have to pay with Java - which carries a lot of baggage with it to make the bytecode compiler happy that "agile" languages like Python and Perl (especially Perl) don't worry about. If they *really* need performance, they'll write it in what Linux developers invariably resort to for such a task: C.