Wouldn't that change drastically between styles though? I can see Iwama and Ki being beautiful, but from all I've seen, Tomiki and Yoshinkan is considerably less wavey, smaller, and more to the point. In all demonstrations I've seen, I would never describe Tomiki as "beautiful", especially not during competitions!
I guess it would also depend on your ideals of what beauty is? I'm not so familiar with Tomiki or Yoshinkan, but they do seem to have more of the practical and competitive nature. Some of the practitioners are still beautiful to me. When you see someone with that look of concentration, doing what they love, and on top of that, doing it well, sincerely, and as someone said before, honestly, I think that's quite beautiful too. Of course, it they can do it with cold cut precision, there's admiration for that too.
There is beauty in a lion taking down an antelope, IMHO. It can be messy, and sometimes awkward, but it is life--it does take lots of skill and practice but the movements are like... a part of nature... and now I sound like a hippie. But, I think my point is if you're always looking to improve--your stance, your technique, how you look and feel, and how much you give when you're doing it, you'll not only look beautiful, but you'll excel too.
To me... it's sort of like... the amount beauty is parallel to your mental and physical improvement, not just an optional incidental benefit to getting better in Aikido. Which is why I use it to "judge" whether someone is really good or not. I don't know who said it, but the most beautiful things in nature are often the deadliest and most efficient... although beauty seems to be a sole human concept.
Can a person who doesn't have an artistic bone in their body still appreciate beautiful art? Can a person who does sumi-e professionally still appreciate the technique of someone who does watercolor professionally? That's sort of what I see when I look at other styles.
Or something like that. o_o;;;