It seems to me that what Kaufman is saying is that artistically, following Balanchine is only going to take us so far. Many of Balanchine's creations are quite dazzling the first few times one sees them, but after that, his conventional choreographic devices start to wear on one, and there is frequently not much else there to support them. (His formulaic 'homage to Petipa' tutu ballets come to mind.) I find that the 'less is more' formula really did seem to work well for Balanchine: when he doesn't have sets or costumes or 'easy' music, his choreography is much more interesting, albeit perhaps only from the point of view of choreographic and/or technical theory. Unfortunately, his choreographic imitators do not have his ability with abstract and plotless dance, and while 'The Four Temperaments' and 'Agon' pushed the notions of what ballet was (and is), ballet choreographers have not taken us beyond that, and even their imitations lack his perfect, diamondlike structure. Thus, whereas Balanchine's black and white ballets have (IMO) the most choreographic substance even if robotically performed, his imitators give us expressionless dancers performing choreography that is not even interesting from a theoretical standpoint. However, skilled dancers and choreographers, even if not geniuses, can take even conventional steps and use them in service of expression. Tudor, Ashton, Bournonville, and Petipa all did this very well, but the electricity their ballets (and plenty of dancers performing today) can create is largely ignored by AD's and choreographers who think high legs, spinning, and fussy choreographic embroidery are the only things that sell tickets.
In short, Balanchine's ballets are lovely, but empty imitations of his style are just pale, lifeless copies, however fast the footwork and however contorted the limbs.
NOTE: Apologies, miliosr posted whilst I was writing.