I think they have the right idea but for the wrong reasons. Having a person whose sole job is to play devil's advocate on every idea can help minimize the risks of group think. Often truly bad ideas are not a mystery, plenty of people on the ground level of a company think they are bad ideas but also know that speaking out will hurt them politically within the company. There is nothing a company can do to prevent this feeling, it's a natural part of human behavior. Having someone who does nothing but question and criticize might give these voices a safe channel from which to express their perspective, preventing bad ideas from moving forward in good companies.