@Trevor - Seriously? Almost every major success? I think that's unlikely unless you're defining Lean methods extremely broadly. For example, do you count all the companies that did "customer development" as being Lean? Because that was part of UCD long before it was part of Lean UX.
But even if I concede that lots of successful companies used some piece of Lean, it still doesn't mean that other companies should become Lean as an END. If Lean methodologies don't help you get where you're going, why would you use them?
It's like saying that most successful products get transported by train, so if you're making a product, you should transport it by train, even if the train doesn't go anywhere near where you want your product to go.