It probably could be clearer, but I suspect one problem that the developers were trying to avoid: is C a text scalar?
S = ['ab';'cd'];
C = {S}
isscalar(C)
iscellstr(C)
C is a scalar and it is a cellstr, and so you could argue it is a text scalar. But the text it contains isn't really one piece of text. To me that "feels like" two pieces of text data (stored as a char matrix, not a char vector) that happens to be stored in one cell of a cell array. We could make the description of what mustBeTextScalar does more complicated (it has to be a scalar string or a row char vector or a scalar cell whose one cell contains a scalar string or a row char vector) but that's starting to get harder to parse (for a human, not for MATLAB!) And then if we define "a scalar cell whose one cell contains a scalar string or a row char vector" as a text scalar, does a cell array containing that count as a text scalar?
C2 = {{'hello'}} % text scalar or no?
Lest you think that an artificial example, well it is since I wrote it up myself. But if you have space padded data (so that two pieces of text can be concatenated together) it looks a little more realistic:
C3 = {['apple '; 'banana']}
celldisp(C3)
iscellstr(C3)
isscalar(C3)
