Well, Microsoft wasn't trying to "Kill Java". They were accused of trying to kill "Java portability". which isn't the same as killing Java (Try porting android Java code to IOS for example).

The claim is that Microsoft omitted the Java Native Interface (Allows Java code to call C/C++ code) and instead used their own J/Direct interface for calling Win32 APIs directly.

That said: 1. I have to admit J/Direct was an awesome idea. Being able to call Win32 apis directly without writing JNI wrappers is very useful. You wouldn't be able to port python code that uses the win32api module either.

2. JNI Code is very often not portable as it is. If you're writing JNI Code, you're most likely already using native OS apis, and relying on OS specific features.