[dtheodor]

We often see criticism against unit testing that is based on facts such as tests are badly written, unmaintainable, incomprehensive, and they drag development down.

Which may very well be true! But I am amazed at the conclusion: That because tests are badly written, writing tests is a bad thing. No! Any code can be badly written, it doesn't mean that writing code is a bad thing. Tests, like any other piece of code, also need to be designed and implemented well. And this is something you need to learn and get experience with.

As to whether well-written unit tests are worth it, I cannot imagine how someone could efficiently maintain a codebase of any size without unit tests. Every little code change is a candidate to break the whole system without them, especially in dynamic languages.