Because you say that the multiverse "cop out [...] *clearly* cannot be proven". Yes, this is completely illogical.
The multiverse thing(or "many worlds interpretation") states that the universe "splits" in several versions (or "branches"), all legitimate and real, but that cannot interact with each other. That's what "parallel" means. They don't converge. Otherwise, they wouldn't be "parallel". Hence, yeah, we cannot, by definition, detect any "parallel universes". That means "it's scientifically proven". Hawking believes, as far as I can understand, that it's just a propabilistic formulation. Which is the most rational thing to assume and give it a day, unless of course you're not obsessed on reenacting SG-1 on real life. Of course, these days, for many people "proof" means that the maths work out...I am entitled to my opinion that, if you say that the universe splits in "branches", I require you to go and bring me proof that other branches are actually physical. Go bring me a rock from the alternative universe. Notice, I say *physical*. That other branches, not communicating with out own, actually *exist*, not as a theoretical possibility, as a reality. Otherwise, it's just bad sci-fi poppycock.