Numbers transformations dimmed with multiple cells selected

Need to transform the case (upper case; lower case; capitalize) of text cells after making a selection such as an entire column of text cells, or selecting multiple text cells.

The menu option Edit ... Transformations shows only dimmed options when anything other than text within a single cell is selected. Further, selecting a cell [by single click, not selecting the text itself] does not enable case changes.

Is this a bug or by design or...?