> I am in the fortunate position of writing an in house Django app, so basically it is in a constant beta state, and I have around 40 beta testers to tell me when things go wrong.

And I'm sure you can see that if you were in a position where you had thousands of external paying customers relying on your service (who will possibly leave and stop paying if it breaks) that you might appreciate having unit tests and other automation to help you worry less when it comes time to push the big green launch button.