Since the green Sort Cells option in the Pivot Report only applies to sorting pivot cell values, it would make sense and improve over all usability that only Cell data values appear. Currently, all data values in the report including row and column data values appear. This is misleading as it leads the user to believe that they can also sort on Column and Row data values which isn't the case.
There is a separate idea already submitted to be able to sort on Columns and Rows. But, until that day comes, this is a usability safeguard to prevent misleading users to believe they can also sort on pivot column and row values.
I LOVE this idea and think it is the bomb.com Please make this a reality soon so my users stop trying to sort things that are fundamentally unsortable. Thanks!