"The launch is also taking place in California, rather than Florida. This means the rocket can't do the most efficient eastward route,"
No. It is launching a polar orbiting satellite. An Eastward route is not more efficient for a polar orbit, in fact it is impossible to reach a polar orbit insertion launching to the east. The whole point is that the launch MUST launch to the west in order to wipe off the entire rotational speed of the Earth. You need the orbital motion to go over the poles, not over the equator. It launches to the west from the west coast for the same reason eastward launches launch from the east coast. To avoid flying over populated areas.
"Which begs the question why is SpaceX doing it?"
"begging the question" has nothing to do with asking a question in response to something. It means to assume the answer to the question. It is a contraction of "beggaring the question". "Begets" the question perhaps, but "begs", is just plain wrong.