The drama is mostly because lots of people don't like writing tests, and lots of folks at one point or another have seen unit tests that are questionably valuab

The drama is mostly because lots of people don't like writing tests, and lots of folks at one point or another have seen unit tests that are questionably valuable or past the point of diminishing returns I think of tests that require a bunch of scaffolding to mock out any meaningful logic in order to test a single, simple if statement that invokes some other business logic that is already meaningfully tested on its own. At that point, it's easy to say "Wow, a couple of E2E tests would have caught the whole shebang!" Maybe I've just been burned by how easily one (read: I) can accidentally write pointless unit tests in Python. I think the unit testing "debate" when it comes up tends to be very handwavey, like this article (which I still think is thoughtful.)