It is as it says.
1) Cloud Atlas is a crushing 164 minutes long. I have absolutely no problem with long movies, but this is the cruelty that makes these other sixty-five abuses of the cinematic form possible. If you're going to bind your audience to their seats for nearly three hours, you'd better at least have something of substance to sustain that kind of runtime.
2) So what does Cloud Atlas attempt in this generous frame, exactly? Everything. It's less a movie and more a shameless, pearl-clutching missive on the ills of the world. There is a desperate lack of focus to its sociological ranting - the class system, "natural order," human bondage, identity and cloning, race, homophobia, nuclear power, capitalism, greed both private and corporate. It never ends. And that doesn't even include the porridge of grander philosophical concepts bubbling under all this...
3)...reincarnation, predestination, the infinite rippling of causality, the existence of a soul, religion and belief. On their own, all of these things are interesting, which is why movies are made about them. When they're all crammed together, dispersed over six different narratives, and then delivered with all the grace and subtlety you'd come to expect from the folks who made The Matrix, it turns into a giant, unwieldy, overstuffed sack of hot nonsense.