If anything Muta, I would say your defence of the rust and rocks is far more honestly given than others. Most of the people defending this piece in this thread weren't even willing to actually defend it. They just wanted the platform to brag about their own superiority.
That said, I agree that it can be called art given "art" is loosely defined at the best of times and it was certainly commissioned as such. However, the simple fact that it causes people to talk does not make it
good art, even from an artistic perspective.
This video, for example, documents what can also clearly be considered art, and it certainly made people talk. But that neither made it artistically valuable nor, something that retroactively justifies its need to exist.