Why Most Unit Testing Is Waste [pdf]
The normal practice for large scale codebases in complex domains is "the code is the spec". That is, the only specification for how the system should work is how it worked yesterday. 
In that case, unit tests serve as a great specification. Even tests that just duplicate the business code under test and assert that it's the same (A huge waste in normal cases) is useful. Because a Unit test is much better than a word document in describing how code should behave. I very much prefer a massive, hard to maintain set of poorly written unit tests, to a large number of outdated documents describing how every bit of the system should work.So is a big/bad test suite a burden? Sure. But is it a burden compared to maintaining specifications of other kinds? Is it a burden compared to working in a system with neither type of specification?Further, the people writing long articles like this are (or at least were) very good developers. There is often an element of "good developers write good code, so just use good developers" in them. But writing good software with good developers was never the problem. The problem is making software that isn't terrible, with developers ranging from good to terrible, and most being mediocre.