The only lifelong, reliable motivations are those that come from within, and one of the strongest of those is the joy and pride that grow from knowing that you've just done something as well as you can do it.
Nothing in life is static; it either gets better, or it gets worse.
It is not a question of how well each process works, the question is how well they all work together.
If there is no worker involvement, there is no quality system.