Is Django a good choice for a security critical application?
The reasons for building banking apps in Java are not related to security, at least IMHO. They are related to:

Java is the COBOL of the 21st century, so there is a lot of legacy code that would have to be rewritten and that takes time. Basically banking apps are old apps, they were built in java some ten years ago and nobody wants to throw all the old code away (which BTW is almost always a bad decision),
some people believe that a static typed language is somewhat "safer" than the dynamic typed language. This is, IMHO, not true (take for instance collections prior to Java 5).
Is Django a good choice for a security critical application?
I am asking this because most of the online banking software is built using Java. Is there any real reason for this?