I don't think Science can ever truly answer the question "what caused the Universe?", so in that sense I can kind of see the point. I also get why it is difficult to accept an answer along the lines of what beso and I have been saying, which in essence amounts to "the question makes no sense because the Universe itself defines its own beginning", or some such.
But part of the reason they are unsatisfying, I think, is that trying to express in language concepts that defy any logic is always going to be tricky. Try and picture nothing, as in a literal absence of anything. You've failed. In order to see "nothing" you need "somewhere" to stand, and by definition there wasn't even a place in order to observe the total and complete absence of anything until our Universe came along -- at least, that is, if you reject the existence of a "Multiverse".
One resolution to this is to try and take the question away from language and towards Mathematics. The maths for describing the Universe as it exists, especially in the context of General Relativity -- which is what's relevant here -- is Differential Geometry. This helps to remove the imprecision. Space and time can be described in terms of some complicated four-dimensional shape, a "manifold", which exists in and of itself, defines its own limits, and needs nothing else in order to justify its own existence.
Of course, this may not be the final resolution of the problem either -- but it is at least likely to be a better way of trying to formulate the question than anything else attempted so far in this thread.