We've been following this feud for some time here, so you may be interested in the latest salvo.
The most interesting part of the article to me is the question of an adequate definition of "nothing." I don't think the one they propose is actually adequate. If you shrank the universe to radius zero, there would still be fourth-dimensional extension -- that is, the universe would have been. If you compress the time as well as the space, so that the universe in this sense never was as well as isn't anywhere, you've still got the potential for it to have been: after all, it was, before you started shrinking.
True nothing needs to be an absence of potential, not just an absence of actuality. It may be that there never was (in the more usual sense of the phrase) an absence of potential; if so, there was never nothing. Existence is then necessary: even if you reduce the universe to "nothing" in the sense the author means it, something still exists. That field of potential still exists.
But why is there something and not nothing? That was the original question, and all we've accomplished is getting back around to agreeing that there is something.