[kortex]

That to me sounds like a difference of degree or heap problem, rather than a categorically different condition.

Sure, welding back on a hardpoint that broke off a plow is concrete and obvious (maybe that's analogous to fixing a broken dependency that got renamed), but there are other fixes that definitely fall under "I don't know why it works but it works". I've had electrical gremlins and fixed them by grounding something that looked like it ought to be grounded, and was grounded when I tested for continuity, but nonetheless was acting floaty. It was probably a loose connection elsewhere in the system, but I didn't know that for sure, nor do I even know that it was the problem in the first place.

Software definitely reaches insane depths of complexity, but again, if you can dig down and understand the abstraction well enough to attempt a fix, and the problem goes away, isn't that good enough? The real difference is mechanical systems typically only have a few layers of abstraction, while software has dozens to thousands of layers of abstraction.