If they are pulling out then her chances are a lot lower of becoming pregnant you realise? No, pulling out doesn't work as actual birth control, but it WILL be a detriment towards a woman becoming pregnant, so if she wants a kid, the man needs to be ejaculating inside of her!
This example is why people *think* pull out is a method. It's not; it just so happens that every now and then a slightly less fertile couple does it and they go "Oh look, pull out kept me from being pregnant!" when it was actually her body.