I don't think there is so much of a difference between the deliberate decision and the accidental implementation of an incomplete or broken feature. I have wri

I don't think there is so much of a difference between the deliberate decision and the accidental implementation of an incomplete or broken feature. I have written software with tests and without. The latter start like prototypes and become quite useful over time. At first, everything looked good and there where just very few minor bugs which could be fixed easily. But over time, there appeared more edge cases which cannot be tracked down. As there are no tests, there are no specific definitions of what each part of the software is supposed to do. Yes, there is a big picture of how everything should work together, but obviously it doesn't catch every edge case. The problem is, that as a developer I can't act as effectively on my code anymore, because I took some shortcuts in the past. On the other hand, there are other projects where I have test suits and where I can be totally confident, that everything has a well defined spec of what it should do and where I can't break something accidentally without noticing it. So in the end it doesn't matter if your shortcuts have been made deliberately (most of the time it is a mix anyway). What matters is that due to the shortcuts you can't act as effectively on your code anymore.