@brokenshoelace, I think people are talking about slightly different things here. One thing is "natural" abilities, other is the result of those abilities being polished and developed over time (which is what we see and what I believe you are making reference to).
People seem to be believe that they are able to identify that "original" talent in everyone. Well, maybe they are, sometimes you really get that impression, but I take that with a grain of salt anyway. But that there is something "inherent" to each player, there is no doubt about that (and, yes, I know that this is implied on your posts).
One example: ask a neuro-psychologist how professional athletes (football players, for example) in general fare in their tests (which are done with pen and paper). Usually they are very good at the ones which require quick answers and/or some degree of coordination/space orientation. They never trained for that. This is (one example of) "natural talent". Again, the question is: what you do with those talents?
Another complicating factor is that "tennis talent" is the result of a lot of different, individual talents. To be good at the net, you need quick reflexes and a soft touch (and technique, as well). Kyrgios -- to go back to the one of the "case studies" here -- has tremendous reflexes, an ok touch and an ok technique (which should come from training). So depending on how you look at it you can say that he is "oh, so fantastically talented" or just a "decent/good" volleyer.