We mildly assume, quite naively I believe, that there shouldn't be anything, that nothing should exist at all, if there isn't some grand creator to make it. This assumption led philosophers like Leibniz to ask why there is something rather than nothing, because intuition would tell us that nothing should somehow be the default. I can understand this notion of nothing being the default, however, I also recognize the fact that our intuition has been misguided before.
It may be as it turns out, that something must always exist, that absolute nothing has never and could never exist. If this is indeed true, than our arduous quest to explain the meaning of existence is futile at best. In my journey in understanding philosophy, I have come across the term brute fact. In order to give a sufficient explanation of something, you cannot have an infinite regress of explanations. As it seems, and you must eventually arrive at some terminating point. For theists, that point is god. God is their brute fact. For the naturalist, it may be some fundamental law that necessitates existence.
Existence and nature might just be brute facts, and so it may be futile to ask why these laws of physics and not others, or why this universe and not another. I myself have wondered why this god and not another, and why did he create this world and not another. The former at least is explained by theists that god's own existence is necessary for some reason. What that reason is, varies from theist to theist, and religion to religion, but I've also wondered why there shouldn't truly be nothing: no universes, no laws of physics and no god. And since god is a mind, I've wondered if god ever reflected on his own existence, and why it is that he exists, eternally.
Personally, I contend that god's purpose is to create us, and that without us, or without creation, god serves no purpose unto himself. If it is indeed, as I believe, that existence is the default, that there is always something rather than nothing and that there has never been and cannot ever be absolute nothing, than it's no surprise we created many gods and myths to in order to explain our existence. So asking why there is something rather than nothing may be the wrong question. The better question might be, why isn't there nothing rather than something?