There's a time and a place for it. If you already know exactly what the program needs to do, then sure, design a user interface. If you are still exploring the design space then it's better to try things out as quickly as possible even if the ui is rough.
There exist other ways to do the research. „Try things out“ is often not just a signal of „we don‘t know what to do“, but also a signal of „we have no idea how to properly measure the outcomes of things we try“.
But that’s the point, no? Prototyping is useful but beyond a proof of concept, you still need a suitable user interface. I have no problems if there’s a rationale behind UI changes, but often we have stakeholders telling us to do something inconsistent just so their pet project can be presented to the user. That’s not design.
The latter is an interesting mindset to advocate for. In almost every other engineering discipline, this would be frowned upon. I suspect wisdom could be gained by not discounting better forethought to be honest.
However, I really wonder how formula 1 teams manage their engineering concepts and driver UI/UX. They do some crazy experimental things, and they have high budgets, but they're often pulling off high-risk ideas on the very edge of feasibility. Every subtle iteration requires driver testing and feedback. I really wonder what processes they use to tie it all together. I suspect that they think about this quite diligently and dare I say even somewhat rigidly. I think it quite likely that the culture that led to the intense and detailed way they look at process for pit-stops and stuff carries over to the rest of their design processes, versioning, and iteration/testing.