The goals they have are good ones. If you're stuck with more than 10 programmers of varying levels of ability, and you're taking marching orders from a client who has no idea what the tradeoffs are, they're arguably the best way to get things done.

When you're a group of fewer than 5 programmers and you're all smarter than the average bear, they're useless.

In essence, they're a ritualization of the communication and testing process that has to happen to make software good and reliable. Without some communication and testing, the software will suck; at a certain organizational size, or with programmers of lower ability levels, you can't rely on the programmers to do it themselves.