Why is there a Universe? Scientists simply don't know how to address why questions. They are out of the present formulation of modern science. Nor do we know, or have any prospect of ever knowing, why there is a Universe.
When you think about it the condition of first non-being, preceding existence and then death for those creatures lucky or unlucky enough to have emerged into existence is a more accurate description of the disposition of organic matter than so-called "living" which is only a flash in the pan.
The Grand Design exposes a major departure on the part of physicists arising from the realization that there is no single theory, or for that reason, a single reality, that can be ascribed to the universe.