Emotions, sensitivities, etc. aren't interchangeable. This discussion reminds me of the debate over design in the universe. An atheist physicist once said in a debate that every person was an improbable event. One in eight billion. Another physicist later corrected him that the odds of being one person out of all persons was a bad analogy in that simply being a person "won", and the arguments concerning design were essentially saying that all the other outcomes, besides one, resulted in no persons. No one is suggesting that "any" emotional state will do. But there are certain states that matter.
Dexter Gordon started out as a promising young tenor sax player. But problems with addiction drove him to squander most of his gifts. Yet he is also recognized as having made some of the most soulful recordings of all time.
Consider:
http://www.youtube.com/watch?v=k2Lx3n10fkc
No one would argue that the above is technically impressive. But most persons would recognize the extraordinary feeling contained therein.
Billie Holiday was far from being technically excellent. A former prostitute, she had a horrible voice and no chops to speak of. Almost anyone alive would tell you that Ella was superior in every way--except one. Billie Holiday was capable of a monstrous amount of feeling.
But again... Billie or Dexter could feel the most incredible degree of "feeling"... but it would all be irrelevant if they could not communicate this successfully to others. Every adolescent feels the most incredible emotions. At that age they imagine they are the center of the universe. Suzy gets dumped by Johnny and imagines that it is the end of the world. She spews forth her feelings in her journal... but almost none of us would think to suggest that the resulting work is likely to be a poetic masterpiece. All that has been said here is something that should be obvious: whether one is a virtuoso, an academic, or your notion of a "natural" artist, all art demands a degree of study, practice, and discipline.
Both of the above examples are fairly unimpressive technically, but emotionally they are outstanding. To listen to those recordings and try to discuss technique is to miss the point. It's about the soul, the duende, brother. Both of those artists had hard, and in some ways disappointing, lives, and their sensitivities and emotions were central to their artistic statements. To suggest other people have emotions too is to miss the point. We're not talking about one in a million in which all the other 999,999 are winners too. We're talking one in a million in which all the other 999,999 fall short of the criteria.
I don't think the notion is to suggest that all art can be broken down or reduced to some collection of elements. It is virtually impossible to offer up a catalog defining just what exactly makes Rembrandt or Miles resonate so. If we could do that, we'd all be capable of producing the same. What is being questioned is the rather juvenile and Romantic notion that all one needs to become a masterful artist in whatever genre you choose, is some degree of strong feeling. How many horrible works of art, music, poetry etc... are produced with the utmost sincerity of a deep feeling? How many artists/poets/musicians had disappointing... even tragic lives... and yet fell far short of producing art of any lasting value?

