For conceptual re-use, we often need a quick scaled version of an existing assembly. This would require scaling all parts, assembly features, sub-assemblies, and assemblies. Current behavior requires the user to open every single part, sub-assembly and the top assembly to manually change the scale. This would be a huge time saver on large assemblies.
NOTE: Relations can make this challenging since there is no way to know the proper way to scale numbers and/or angular values found in relations. If the scale routine identified parts with relations that might be affected by scaling, this would be also be helpful.