This may be the first time I've agreed with Dawkins. At least in part. Specifically, his statement that the idea of "purpose" in the universe is inextricably linked to theism.
The first important point is my premise that "purpose" is inseparable from "mind." You can't have purpose unless you have a mind. And to infer purpose in something is to infer that a mind had purpose for the thing.
We can of course infer purpose from the remnants of human or animal actions -- but that is because those beings have minds. To infer purpose from the arrangement of the solar system, or the existence of biological life, is to infer that a creator exists, and arranged matter in such a way as to put his purpose into action.
It's also important to remember, though, that just because there's purpose in the universe doesn't mean we have to like it. There is purpose in a slaughterhouse -- but that doesn't mean the cows know what it is, or should like it if they did.
There's a third issue as well. Just because some things in the universe reflect a divine purpose (like say the origin of life), does not mean that everything in the universe reflects purpose. The shape of a particular mountain, or the cancer of a particular friend, may well be just as purposeless as they appear.
The question of whether there is purpose in the universe is inextricably linked to the question of whether the universe was designed. But the question of whether we like that purpose is a separate one entirely. And just because some things may reflect purpose does not mean everything does.