Sure, but it's hardly a reason to write unit tests.
I write unit tests for every one of my core algorithms. I have also seen a massive amount of dumb tests written by TDD people who strive for 100% code coverage. Ridiculous. It takes as much time to maintain the (often useless) tests as it does the code. Where they make sense they're indispensable.
Agreed. It's not a reason to dismiss tests though.
I think the fundamental question is why 100% code coverage is important. The fact is that it isn't. the problem with TDD is that a lot of people who do it totally get the idea of why you are testing entirely wrong. The goal should never be to "ensure your code functions properly." The coal should be to "ensure the code contracts are adhered to." If you test with that in mind, you will write lots of unit tests and almost never have to rewrite or delete them due to fixing bugs.
Again this comes back to what I said in another comment that tests should never be written to the code. Once you get that, then code coverage ends up being meaningless and not something you want to worry about.
I write unit tests for every one of my core algorithms. I have also seen a massive amount of dumb tests written by TDD people who strive for 100% code coverage. Ridiculous. It takes as much time to maintain the (often useless) tests as it does the code. Where they make sense they're indispensable.