I really believe that if we all knew what exactly the formula was that the USTA uses and had the level of transparency you describe many more players would be happy with it. Even though I suspect that the USTA system is much more convoluted.
Unfortunately, I have come to realize that USTA has created a National championship structure that rewards players who manipulate the system, so this level of transparency is problematic.
At this point I wish that all USTA team tennis would become local leagues and that the ratings system became merely a way to get like ability players together on the courts rather than an attempt to normalize players across the states.
"You should be playing linebacker, not singles."