The seven-point scale was originally presented in The God Delusion as an enumerated list of positions on the question, not as a continuous scale to be mapped to probability. Though of course you can bend it into one, as Dawkins implicitly does by saying "6.9".
More generally, your comment reads a bit like Lukeprog's review of Carrier's Proving History: Lukeprog considers it failed advocacy for Bayes because of its topic (the historical Jesus), whereas Carrier considers it a book on historical methodology using the historical Jesus as his example, because that was the precise topic he was being paid to write on. I think authorial intent does count.
I agree with your first paragraph, though in the interests of authorial intent, I'd like to stress that I don't think that Dawkins subscribes to Bayesianism and I don't think that The God Delusion has anything to do with Bayes. I was saying, 'this is about as close as he gets to Bayesianism and he's not quite there, which is a pity because he would have made for a good advocate. The best you could say is that he's tacitly using similar logic in certain places, one example being the seven point scale.'
http://bigthink.com/think-tank/neil-degrasse-tyson-atheist-or-agnostic
Apparently Dawkins and Tyson give a non-zero probability to "God". Which is pretty much what is expected of a rational person. And of course it will be used by theists to say "They aren't really sure!"