It's as matter of practice. The major problem is that business folks don't even know how to produce a testable spec, they just give you some vague idea about what it is they want and you're supposed to produce a PoC and show it to them so they can refine their idea. If you go and produce a bunch of tests based on what they asked for, but no working code, you're getting fired. The whole process is on its head because we don't have solid engineering minds in most roles, we have people with liberal arts degrees faking it until they make it.

There were a few places I worked that TDD actually succeeded because the project was fairly well baked and the requirements that came it could be understood. That was the exception, not the rule.