Yeah, the OP's counterargument is that you can filter down what goes into the test output. But at that point it seems not too different qualitatively from the traditional bottom-up approach where you just write assertions yourself, except that the framework does the job of populating the assertions' expected values.
If you are saying this approach would tend to produce a lot of change-detector tests, then that is an issue, but I think scotty79 is making a different point: this approach would seem to make it easy to overlook any regressions that the latest change has created.