Asking "why" about everything is invalid. In some cases, it's appropriate instead to ask "how". My kid is currently 3 years old, and asks "why" about everything(and I love it).

Nested within the question is the assumption that the answer will be teleological. It is an appropriate question to ask when wondering about a person's intention. It's an inappropriate question to ask when wondering about many large questions in science. You have to justify the teleological assumption first, and show us there is "intention" towards which the question of "why" can be asked.

Science is answering the questions it's able to bite onto. Most of the "why" questions are misuse of language, rather than a failure of science.

11D actually was first postulated nearly 60 years ago using the Standard Model. ( http://en.wikipedia.org/wiki/Standard_Model ) It sat there as a possibility until it was pushed into prominance with String over 20 years ago when String ideas started to prove themselves as the only possible way of expanding the Standard Model to encompass everything. Since the 11 D Standard matched 11 D String this has become the key for advanced theories during the last 20 years. So we are referring to an idea that is half a century old and has survived decades of scientific debate and has only gotten stronger support. The Wired article has been based on incomplete data. This is common with popular journalism. Even journalists in technical magazines don't have the required background to have followed fully the debate.

The idea that main stream science doesn't consider String strong enough is invalid. Everyone of the top theoretical physicists in the world use String. Hawking is not alone in his use of the theory.

By the process of elimination. Most 'reasons' and 'evidence' people have break the rules of logic, or are non-sequitur. If there is evidence somewhere out there that has some bearing on the question, I'd be surprised. Biblical texts? Anecdotes? Miracles?