...why is it so easy to give credit to the natural selection process, but not be able to give credit to something putting that process into motion?
What do you suppose the "natural" in natural selection means? Why would a natural process need to be put in motion? What does that even mean? How could a process like NS not work in an imperfectly reproducing population? Seems like it would require outside intervention to stop it, not to start it.
Unless I miss my guess, your real question would be more accurately stated as "why is there something instead of nothing". Could we just skip the next several hundred wasted posts and say "don't know" right now?