Very surprising coming from a Fed fan I must say. Well, In terms of tennis ability, Fed is more gifted. However in terms of athletic ability, Nadal is way more gifted than him.
look at the threads I started there is one or two about that.
Ahletic ability is a part of tennis ability imo. There are also some inner mental skills.
But yes the whole problem comes from the definition of "talent" : for me it means "natural gift", for others it mostly means "hand talent" ... as if anybody could reach a great physical or mental level just by work, I agree with you, that's completely wrong. And I think that many skills which are considered as "talent" are more about technique ... and technique can be worked about.
Tennis used to be much less physical and in that time the notion of "talent" which people usually have in tennis was much much more suitable. But tennis has completely changed : tennis is not a welcoming place for Nastases anymore.