As other reviewers have noted Krauss's " nothing", a vacuum nothing, is different from the original sense of " nothing"', as absolute non-existence, which was its sense when the question was first posited by Leibniz.
Because of this purely semantic difference Krauss is not actually answering the question, as originally stated and still commonly understood, as to why there is something rather than nothing.
His notion of "a potential for existence " merely moves the question back a step i.e why is there a potential for existence rather than nothing.
This is not to claim Krauss 's theories are wrong (or right), merely that he is answering a different question.
My take for what it is worth is on the original question...
As to the question as to why there is something rather than nothing the common sense response would be....Well, why not?
We know the universe exists, but cannot know any good reason why this should be surprising or mystifying or in need of justification. ( to say you are puzzled etc is not a good reason, it is a statement of your psychological attitude).
We have no basis to judge whether it is more " natural" for something to exist or for there to be nothing. We cannot stand outside the universe to possibly form any basis on which we can make any kind of answer to the question as to why there is something rather than nothing, we have no vantage point from which to compare the relative likelihood of different modes of existence for the universe ( in this instance something or nothing) , and a question which cannot be answered is meaningless. Somewhat akin to asking someone to explain why a cat has 5 legs.