Well, I do not think that it is inappropriate to discuss the outer appearance. We do it in our everyday lives (well, at least I do) - why not here? As long as we do not bash skaters because of their looks or judge them by their looks and not by the skating - we cannot do much harm. But the hair-do, or the costume, cannot really upset me. Skaters are different people with different styles and different hair-dos and costumes that fit them. For that matter:
I absolutely love Takahashi's hair... It looks amazing and it is just different from most skaters, but especially from the Asian ones. I cannot even tell the Chinese guys in pairs apart - they all look the same and not because they are Asian. Lots of Asian guys at my university have similar hair-dos. Why shouldn't Takahashi skate with hair like that? He is a young guy, who probably loves going out and partying like nearly every kid his age. Adore his costumes too...
I also think that Johnny's hair suits his style - he seems like an artist, I could not imagine Johnny with Daisuke's hair or Joubert's successfull-lawyer-cut. But Joubert's hair-do suits him, his skating-style and how he presents himself. Plushenko looks great with his hair, too - most people could not wear it, but he can.