You are interpreting "why is there something rather than nothing?" as "Given the observed laws of physics, why is there something rather than nothing?", when what is being asked is "Why are the laws of physics these laws which you say makes the question 'why is there something rather than nothing?' meaningless instead of some other laws that result in there being nothing?"
The suggestion that the laws of physics could have been different is just a hypothesis, and that class of hypotheses usually involves some form of a multiverse scenario in which all the possibilities are realized in different universes. The idea that there is one universe, and something caused it to have these laws instead of laws which lead to nothingness, is a terribly contrived dilemma.
From an empirical point of view, we observe the laws of physics, and speculation about other laws is unjustified. From a philosophical point of view, it makes much more sense to think that we observe whatever universe in which we can exist.
This post grew out of a very long discussion with the New York Less Wrong meetup group. The question was, should a group dedicated to rationality be explicitly atheist? Or should it make an effort to be respectful to theists in order to make them feel welcome and spread rationality farther? We argued for a long time. The pro-atheism camp said that, given that religion is so overwhelmingly wrong on the merits, we shouldn't allow it any special pleading -- it's just as wrong as any other wrong belief, and we'd lose our value as a rationalist group if we began to put status above truth. The anti-atheism group said that, while that may be true, it's going to doom us to be a group exclusively for eccentric nerds, and we need to develop broad appeal, even if that's hard and requires us to leave our comfort zone.
Things got abstract very fast; my take was that we need to get back to practicalities. Different attitudes to religion have different effects on different types of people; we need to optimize for desired effects and accept what tradeoffs we must. We can't appeal equally to everyone. So I came up with a sort of typology.
The Four New Members
Annie