It can actually be worse than useless to rely on the "perfect world" of unit testing. I have had a nasty shock, when switching from mocked behavior to real-world behavior. I write about that here: https://medium.com/chrismarshallny/concrete-galoshes-a5798a5...
I'm not going to argue against your experience and from reading the article it seemed like you made the right call. Perfect world testing is indeed a failure, but I would say that "imperfect" world testing is exactly where mocking is beneficial, because it can reliably produce all sorts of anormal behavior. But again, it obviously depends on the situation and circumstances, and good design probably removes more errors than good testing.