Honestly, unit testing good code should have a minimal impact on overall productivity. I'm not suggesting rigorous testing of all possible inputs, but at least

Honestly, unit testing good code should have a minimal impact on overall productivity. I'm not suggesting rigorous testing of all possible inputs, but at least testing one good case and one bad case can save you a lot of headaches and only takes a couple minutes to code in most cases. I mean I agree with your general point in that testing too much is also a bad thing, but too often I hear this used as an excuse for not testing at all. And that's how we end up with legacy monstrosities that you can have no confidence in modifying that so many of us have to deal with.