That's fine to say the ending was artsy and made you think. All true, though I would argue, "To what end?" Either way, the end was totally inconsistent with the rest of the series. The show makes the viewer remember things and understand things, but hasn't ever implied things before. Even after Tony was shot and had the dreams of being dead for a few episodes the viewer wasn't left hanging. Some speculation, sure, but even though it could have gone either way it didn't. Calling the ending an artistic existential triumph is a little much. It's never been that before and shouldn't have been now.