Note that this does not explain where the universe creator came from.
It is possible that the universe in which he lives is fundamentally
different from our own in ways we can't currently imagine, and is such
that life can exist automatically. He then created our universe to
explore the possibility of how our kind of life would work, which is
only possible within this narrow and special range (an advanced version
of the way we play with different rules for cellular automata, and find
that only a limited set of rules lead to interesting behavior).
Of course there are alternate explanations for this coincidence. It
may be that all possible universes exist, and only those for which the
constants are such as to allow the formation of life do have life form.
But that is not a much simpler theory than the one which says that
we were formed out of another universe; both require the existence of
universes that we otherwise have no evidence for.