how is it nonsensical?
It's definitely Art, in that it is making a statement, provoking a response, etc. But, it's just a nearly continuous sound, except for the pitch change every few years.
It's a Sound, but it's not Music.
If you were to argue that it is Music, I would ask, "Which part of the piece is your favorite? Why do you prefer it to the other parts?" Trying to answer these questions with a straight face becomes difficult.
If this is Music, then is it possible to make an art installation which has making Sound as its primary focus, and have it not be Music?
Yes.
You really can't ever say what "the point" of art is. The point of art is that every piece has its own point, or none at all.