Guy Kawasaki also says:

The root cause of mission statement-itis is that most organizations are run by people who have either gotten an MBA or worked for McKinsey’s or both.

He is more positive about ‘mantras’:  ‘a mantra is three or four words long. Tops. Its purpose is to help employees truly understand why the organization exists.’

The ultimate test for a mantra (or mission statement) is if your telephone operators (Trixie and Biff) can tell you what it is. If they can, then you’re onto something meaningful and memorable. If they can’t, then, well, it sucks.