TDD failed because it was sold as a method on how to write better tests yet in reality it was a very challenging skill to learn on how to write software that involved a fundamental change in how you approached requirements engineering, software development, iterations and testing. Even with a skilled team the cost to adapt TDD would be very high for an uncertain outcome. So people tried shortcuts like you described and you can't blame them. The whole movement was flawed and unrealistic in its expectations and communications.