“the biggest defect we have now [in software development] is tolerating defects”
Currently in my workplace, we have some unit testing in place but there are many defects found during our process. I fully agree with Mary's appreciation, defects are a waste in our process and each defect should be a learning opportunity for killig the root cause, so it will never happen again.
Hey, really, if you find the same defect over and over again in your systems, obviously you need to do things differently! IMO, TDD offers a great base for us to use tests for automating such learning (documenting defects is not enough).
Recommended Reading: The 7 Software Development Wastes - Defects