A creature of this physical universe can think up justifications for creating a universe just like the one he inhabits. Is this supposed to be a surprise? Does such a creature really have any realistic comprehension of any other possibilities? Are these justifications supposed to reveal why things are the way they are? Seriously?
I think of the book of Job, and I also imagine how someone 2000 years ago might come up with such justifications according to the way he thinks the universe is like.
If you would really explain why things are the way they are, then you would start with the reasons WHY create a physical universe at all? What purpose is this creation supposed to accomplish anyway? Then you would show how this purpose requires certain features.