So one argument against code coverage requirements is that poor engineers won't test correctly. Without the code coverage requirements you're in the same situation.
Problem is with 100% code coverage of badly guarded / implemented code you'll have a fall sense of security if you're just looking at coverage as the metric of quality. Anytime I've worked with a company who had a required code coverage percent, they never actually cared what the code being covered looked like only that it was covered in some test.
