I find this opinion more honest and convincing than the "it's not stealing if you both get to keep a copy" argument. The latter fails to account for the time, money, effort, inspiration, talent required to create the original work that is subsequently copied millions of times. When the issue of how are artists supposed to make a living in an copyright-less, free-filesharing world is brought up, proponents come up with limited band-aids (live concerts, donations, SaaS, etc).
At least Coppola doesn't beat around the bush: filesharing may mean that professional artists may have the fate of buggy whip makers. Regardless of one's stance on this prospect, this is where the debate should focus, not on the semantics of stealing or new business model cop-outs.
Interesting thought experiment: how would the world look like if all art was created by hobbyists? (honest question)