> code which is hard to test is almost always going to be hard to maintain

This is a pointless equivalence to make. You're trying to suggest that code which is hard to test could be written differently, and better. This is not always true, and therefore useless to say.

STUXNET was very difficult to test. Reports are that it required an entire Israeli nuclear facility as a test environment. Would you suggest that STUXNET was written to a substandard level of professionalism? I doubt it.