Listening to Dick and Peggy Sasha never "suffered" with music IN. Actually had she been a more consistent jumper she would have rarely lost to Michelle as she had several qualities Michelle could never hope to match. Michelle beat Sasha by landing jumps more consistently.
Taste in music is like taste in skating. I liked some of Michelle's music but am not in love with all of it. Same for Sasha.
As I go back and watch YouTube I become more convinced most skaters rarely change their style.
From '95 on Michelle never upped her tech much or changed her presentation style very much. The same is true for Sasha who had a mature style at 14.
Watching a 15 year old Plushenko it is not much different than watching a 20 year old Plushenko or 27 year old Plushenko.
Last year we heard about a "new Johnny" but what we saw was exactly the same old Johnny as in the past.
This season we heard about a new Yuna but I saw the same Yuna as in previous seasons.
Skaters do the best they can and when they fall short or fail to develope to fans expectations it is not because of lack of effort.
Sasha did the best she could and did not blow the Olympics on purpose. I think Shiz was a better skater anyway.
Michelle did not blow the Olympics twice on purpose either and did the best she could under the circumstances. Her case was different than Sasha's as Michelle was the best skater IMO at Nagano and SLC but failed to win. Doesn't mean I like her any more or any less.
Mao is an interesting one to consider. If she never wins the OGM or another WC I will always remember her for the beauty of her skating. That's how I will remember Sasha too.
I tend to agree with you with that there is a persistence of "style" that stamps the work as unique to a particular artist, and that this sense of uniqueness is particularly noticeable in great artists.
One would never mistake (well, at least I wouldn't) a Klimt, a de Kooning or a Picasso as the work of anyone else. The technique and sensibility are always specifically their own. This is a somewhat separate point from a consideration of their artistic "range"; Picasso's paintings deal in everything from love to death to sex to whimsy and humor to fear and loathing (sounds like a combination of Tolstoy, Woody Allen and Hunter S. Thompson

), but the way that these fundamental and universally shared human concerns are considered, interpreted and expressed are always filtered through the sieve of his own irreducible complexities of thought, feeling and manner. (I feel obliged to emphasize something I've said before: this is not to say that an artist (whether painter or skater) is actually feeling the emotion that is being portrayed as they are portraying it, but that they are demonstrating that they understand the emotion and its application to themselves. Otherwise the fellow playing Othello, or Otello, in pairs would be strangling his partner for real

).
Similarly, great actors (Olivier, De Niro, Pacino, Brando, Streep, Dench, even Johnny Depp et al) generally share this sense of the persistence of the actor's individual characteristics, no matter what role he or she plays. It seems to me that the implicit assumption that we subconsciously make, when we see them in a new role, is not that this is a completely different person, but rather: this is how that person (the actor) would think and behave if born in the different circumstance of the role.
The only actor that I can think of right now who at times successfully provided the
illusion of not only inhabiting different circumstances, but of being different people entirely, is Peter Sellers. His multiple personas in "Dr. Strangelove", and his Chance Gardiner in "Being There" were eerie examples of this tour de force technique. But the price that he paid was that the intensity and
authenticity of his expression was diminished, as he deliberately cut himself off from the waypoints of his own personal character. This is why, even in the performances I cited, there is always a hint of lightness, of caricature, that is he always struggling to keep in check. We are amused, we marvel, but our emotions are never fully engaged, distracted as we are by the sense of the slow wink.
The duality of commonality (of themes) and individuation (of expression and style) is what makes art evergreen and suspenseful. It is also why, in my view, the quality of self-awareness is a critical element, in figure skating fully as much as for other arts, and why skaters who can be considered artistically great will also have such identifiable (shall I even say iconic?) styles.
IMO, Michelle and Yuna both have this quality of self-awareness and individuated authenticity in their quality of movement and their expressiveness (and I refuse to get into an argument as to who has it more

). What separates them from many other skaters, again IMHO, is the degree and self-awareness of this individuation, and their success in applying these qualities to a wide range of expressive themes. (I also refrain from critique of other skaters on these qualities, to avoid yet more verbal brawls

). So in a sense, Hernando, I both agree and disagree with you; I agree as to the persistence of a highly individuated style, while I disagree that the performances are "the same", because the theme that they are expressing is different each time.
This is, of course, not to say that they were always and completely successful in fulfilling their aesthetic intentions in every performance they ever gave, but in the sense of authentic individuation of style of movement and expressiveness, they are in my opinion among the very best.