I think his point is that Jackson doesn't derail a Hobbit film in terms of creative output is he is not involved. Because, he really isn't the end all, be all of directors.
However, I do think the film will be derailed if Jackson doesn't direct as I think McKellen and some others didn't want to be a part of it if he didn't. So, pragmatically speaking, the film will suck if Jackson isn't there, because I don't think anyone would be willing to accept a Gandalf that isn't McKellen, but philosophically-- I don't really think Jackson is a requirement. There's plenty of good directors out there.
That said, I do think Jackson gets too much credit for Lord of the Rings. Yeah, he worked hard and certainly went beyond the requirements of merely point a camera and staging the actors, but it doesn't mean he doesn't output shit, which is I think Deni's chief point.
Not gonna lie, King Kong? Kinda thought it sucked. And wasn't his involvement similar?
And now with that said, Lord of the Rings is brilliant. I don't think someone can walk away from it and go: "Well, I didn't like it because of [blank]."
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