From
http://www.history.navy.mil/library/online/uniform_enlisted.htm
9. The Decision to Change - 1970's
In 1973 the most sweeping change in the history of enlisted dress occurred. Based on a survey conducted in 1970 it appeared that there was some fleet desire, principally among the more senior petty officers, for a different, more distinguished garb. Based on these findings, the sailor was removed from his traditional uniform and placed in a suit and tie which corresponded to the officer/CPO style. The intention was to create a single uniformed appearance and present the enlisted male in a uniform which was thought to better reflect the increasing complexity of the modern Navy.
The action to utilize a suit style for all enlisted has been one of the most controversial changes to effect the Navy in its uniform history. From a practical standpoint, the adoption of a different uniform for dress wear was not the result of a requirement. The jumper/bell bottom style had evolved in a work environment where each piece of the garment originally satisfied a need. With the absence of fully rigged sailing ships and the advent of more comfortable work uniforms, what a sailor wears for dress occasions is now a matter of style.
The most obvious impasse to acceptance of the suit and its outfit to the enlisted and general public is that it breaks with tradition. While the components of the jumper style uniform serve no nautical purpose today and are not related to anything worn in the civilian world, it has served to identify sailors all over the globe for too long a period of time. Most navies of the world have utilized a similar outfit and most still retain it for non-rated personnel. Throughout the course of uniform history there has continued a strong resistance to changing traditional garments. Sailors prefer to be distinctively dressed. It was the same in 1830 as it is in 1977.