While 100% code coverage doesn't guarantee 0% bug, it's useful to easily detect new untested code addition and possible bug addition. Another point is that the

While 100% code coverage doesn't guarantee 0% bug, it's useful to easily detect new untested code addition and possible bug addition. Another point is that the code looks obviously right by visual inspection, but we want to automate the check. Relaxing the 100% coverage is a lazy slippery slope I don't take with my code. The danger of 100% percent coverage is that the goal of tests becomes the 100% code coverage and not bug detection anymore.