Before I get into that, let me explain that I do not believe that the material world is all that there is. However, we do not have evidence that there is anything not explainable within the natural world. Souls are not required to explain our self awareness. Love has been shown to exist as a chemical reaction in the brain. If there is anything beyond the natural world, we do not know what it is.
So why naturalistic materialism? Most world views accept that science and reason are the best tools we have for understanding the natural world. This means that everything accountable under naturalistic materialism can also be accounted for under these other world views. However, these other world views claim to have special knowledge that goes beyond the naturalistic world view.
None of these other world views can claim there is something they explain better than other world view without the other world views making exactly the same claim. None of them can prove that their better explanation is true.
With naturalistic materialism, if we are not sure, we can admit we do not know. Claims of miracles and other magical tails that other world views rely on but can never demonstrate don't bother the naturalistic materialist. Since miracles cannot be historically demonstrated as the most probable event because by definition they are the least probable event, we can never know if a miracle took place on history.
Without good reason to accept other world views, we are left with the world view that reflects the best we can based on the evidence, that is naturalistic materialism.