In the classic "swatches panel" with the "direct selection tool" selected, you can quickly select a text box and change the color of the text within without needing to switch to the text tool. You just select the box and click the "T" within the swatches panel.

You can not do this with the properties panel. You have to do the extra steps of switching tools to the text and manually selecting the text. Why can't this feature be available as a part of the "appearance" section of the "properties panel" under the "fill" options.