> not only can you typically do the same job in fewer lines of code when using Python, Python is usually faster as well.
Prove it.
> they prefer to use QT, which is a third party library
What is the problem with Qt being "third party"? In fact, if I had one good thing to say about Python it would be that developing Qt applications is really fast and mostly frictionless. As an experienced Qt programmer, I appreciate that. It is also what makes it useful as a plugin language for applications that already use Qt as their GUI, database, network or sensor access toolkit.