I agree with you that in certain UI windows and wizards, the description (along with Name) of the choices is also displayed. If you read through the presentation to this idea case, I had mentioned that too myself. In 3rd slide, I had given yet another example of such UI where the description of choices is displayed (this is in the assign usage expression wizard upon trying to configure a Configurable Module WTPart).
This unfortunately, is not displayed in the Product Structure tab in the "Assigned Usage Expression" column and thus, my proposal. In the Product Structure tab, only Name of the choice can be displayed in the "Assigned Usage Expression" column and not the description. The proposal is to have a possibility for us in one way or the other to have the choice description too in Assigned Usage Expression in Product Structure tab.
Please review your stand to place this proposal as already existing functionality.