I would encourage you to read a couple other threads on this topic that may be pertinent...
First, a quick explanation of the "shared media" aspect of the system. This knowledge base post summarizes the explanation that the SMs that are far away (or poorer signal levels) may be using more of the frame to complete their data transmissions, thereby degrading the overall sector capacity.
Second, there are some other customer experiences that you can read about here. These guys discuss some of the same points you've made here.
Providing the frame utilization statistic is not changing the performance of the sector in any way, but allowing you to see when you might need additional capacity or make changes to add capacity to a given sector.