I’ve found many people to care for a high unit test coverage. It tells you something about how well your code is tested. Or does it?
Unit tests typically test the smallest piece of code. It is an excellent strategy to write your tests in conjunction with the production code. The tests help you shape the interfaces and help explore the problem domain.
Big question is: does the business/product owner care? What do those tests tell him (or her) about the actual functionality delivered? Fairly little really, if any at all. This boils down to the next question: why care about unit test coverage then?