Getting back to Dawkins for a moment; I see his scale as a declaration from him that he sees "atheism" as being strictly about unequivocally believing no gods exists. With this definition, atheism can legitimately be called a belief as it asserts a fact about the universe in direct opposition to the basic fact which any form of theism asserts. His rating himself at a 6.9 is meant to describe that he lacks such a atheistic belief.
The definition of atheism that I've become comfortable with I describe like this: "The only thing that every single atheist on earth shares universally is that they lack a belief in any god(s)'s existence." Honestly though, I think that quibbling over what atheism is most legitimately defined as is not only impossible to objectively determine (as language is constantly changing), but ultimately useless. We know what Dawkins means as plain as day, and whether he describes his stance in the same way we would makes no difference to that reality. If I ever get into a debate with a theist who tries to base their arguments on people's labels rather than their actual positions, then I try to move the conversation back to the substance. People who refuse to debate on substance are not interested in having an honest debate, and thus I'm not interested in debating them.