The argument is the same as some religious use: science can't explain everything, therefore we need religion. The counterargument is the same too: while science can't explain everything, religion and metaphysics explain nothing. The other inconvenient fact is that lots of things that were previously thought to be not explainable by science have since been explained by science. Science will continue to nibble at religion and metaphysics and the religious and meta-physicists will continue to move the goalposts.