Hiho...Most people, audiophiles included, don't understand servo design, or appreciate the performance potential. Perhaps they have experienced crude servos, like early cruise control in cars, and not been impressed. Most audio manufacturers don't have people with control system expertese, and would prefer to stay with tried and true pivoting arms. Design and development of a good servo arm requires a large investment, and the small market does not justify it.
Besides, pivoting arms work well (if you can ever get them set up right).
Besides, pivoting arms work well (if you can ever get them set up right).