His facial expressions and body movements are not breaking any traditions.
The tradition of using dramatic or sentimental physical gestures date back to the very founder of 'the piano recital', Franz Liszt, who probably wanted to emulate Paganini.
Paganini introduced aspects to the concert which were pricipally unheard of then, but has since become a crucial aspect of especially rock and pop performances:
*he was interesting to look at
*he surprised/entertained/impressed his audience with various tricks and gimmicks
One such gimmick was the famous G-string trick: one after one the strings would break until only the g-string was left, but paganini just kept on playing the very difficult piece, first on three, then two, and finally on only one string, and the audience was left gasping at his unbeleivable skill.
And Liszt, as said, watched and learned..
As the 19th century drew to a close, this sort of behaviour seem to have become more and more antiquated, and by, say, 1950 it was totally obsolete. The only pianist after that who became as famous for his stage behaviour as for his playing was of course Glenn Gould.
Therefore, to say that Lang Lang is breaking tradition by his stage antics is incorrect. Everyone in what you call The Establishment knows exactly what he is doing, it's just that it's passé by about 150 years...
Yes, there are jokes related to him being Chinese, for example: "Lang Lang, a pianist so good they named him twice..", which could be argued to be a bit racist. And perhaps whe have come to the point where it's almost a cliché to see five year old chinese prodigies performing Chopin etudes. Before them there seemed to be a never ending stream of russians. But there are still so many well established prominent musicians with eastern asian backgrounds that your claim that critics can't accept that he's good and chinese has no validity:
Fou T'song
Mitsuko Uchida
Seiji Ozawa
Sarah Chang
Myung Wa Chung
Midori
Yo Yo Ma
Melvyn Tan
to name a few..
The controversy is about the quality of his interpretations versus the way he is being promoted. Every ten years or so, the industry seems to find a budding 'superstar' on the piano, and heavy promotion follows. 1980 it was Ivo Pogorelich, 1990 Yevgeni Kissin and 2000 Lang Lang.
In this thread he has been likened to a rebel, and is said to be 'breaking traditions'. I listen to his playing and hear nothing out of the ordinary. I repeat that, it's ordinary! That is to say, he plays similarly to a bitrigazillion other technically gifted pianists. Maybe that's why the critics aren't very excited (as opposed to what you seem to imply, that they are shocked by this revolutionary new approach that they can't understand, old-school as they are). I, and they, I suppose, hear this sort of playing on every sunday-afternoon-tea-concert, and are therefore overwhelmingly bored by the sheer blandness of it.
And this they have the nerve to call "The new Horowitz..."
Topic: About Chinese pianists