I think most developers agree that unit tests are a good thing(tm). I do agree that the authors assertion that not writing tests come down to A) ignorance or B

I think most developers agree that unit tests are a good thing(tm). I do agree that the authors assertion that not writing tests come down to A) ignorance or B) laziness. There is, after all, a third option. In a startup environment, where you're trying to rush a product to market, unit tests are often just not feasible. It's not ignorance or laziness, it's lack of resources to actually do it.