It's easy to end up with a test that is not about correctness, but "did line 1 get called, did line 2 get called, etc.". Yes, it's easy to write bad tests. But

It's easy to end up with a test that is not about correctness, but "did line 1 get called, did line 2 get called, etc.". Yes, it's easy to write bad tests. But that does not reduce the value of good tests!