Who Makes What Sounds

The Gussenhoven focuses on the anatomic systems involved in how humans produce sounds. The Kenstowicz paper mentions the sounds that a few languages employ but it mostly focuses on how those sounds are represented, making the argument throughout that while we ignorant listeners may hear two sounds as different, the experts have known for a while that they are, in fact, the same. Taking these papers as separate you walk away having just been thrown through an extremely thorough first lesson in linguistic terminology, but taking them together you get many an interesting question from the week's reading. One that I would like to voice hear about who produces what sounds.

The biological function of the "speech organs", as mentioned in Gussenhoven does not vary from person to person yet when you read through Gussenhoven and Kenstowicz you see constant references to other languages when certain sounds are brought up. While this may simply be an attempt to be as inclusive as possible in their respective writings, there are certain times where one is hard-pressed or may find it impossible to come up with an example of certain sounds in certain languages. This makes me wonder, if we all developed these organs to survive and, only after the fact, figured out how to use them to make sounds and then categorized sounds to communicate, why do some languages have sounds that others don't? Is it that some people in the world simply cannot make certain sounds (one example here being the "rolled r" of Spanish)? But even if it's not a genetic barrier to sound making, why were certain sounds more common in certain regions and near-desolate in others?

I'm inclined to not bring it down to a genetic argument because language learners have proven time and time again that, given enough time, you can learn any language and all it's accompanying sounds (some polyglots have claimed to know up to 50 languages). Furthermore, if the production of sounds used in language comes from the usage of the same biological systems we all have in place then there should be nothing stopping us from producing all the sounds of, say, a Nordic language. Yet Californian English is worlds away from that. So then what decided who made what noises and where? If geography is such a huge border system between languages, is it simply that our natural settings came along with their own influence on language? But then what form would that take?