Why are modern arms so ugly?

Because the modern world is .

LOL good one Schubert.  
My vector 4 is like art. 

theo, It interested me that you think the Triplanar is designed and built with a "watchmaker's" precision, because Herb Papier, the designer and for a few decades the builder of the Triplanar was in real life, a watchmaker and watch repairer.  Perhaps you knew that, and it stimulated your metaphor.  I had the pleasure of knowing Herb during his later life, and by chance I was at Herb's house one day during the time when Tri was visiting Herb in order to learn how to build the tonearm.  Herb did it all in his basement back then, with precision machinery of course.  Some small parts were evidently farmed out toward the end or production.

And I agree with Chakster, the Triplanar is now an almost vintage design in terms of years since its introduction.  What makes us think of it as "modern" is the fact that Herb incorporated many new ideas that have become standard fare for modern tonearms and differentiate "vintage" designs from modern ones.  The side mounted tower for VTA adjustment is one.  The placement of the counter-weight in the plane of the LP, so that warps have less effect on VTF is another.  The decoupling of the counter-weight is yet another, although some of the Japanese arms had already done that. And there is the damping trough and the capacity to adjust azimuth.

@halcro 

which arms are ugly???