I do not think it was for any reasons other than the fact that is was one less key to put in the machine. For the same reason my later Olympia does have a bang (!) key, but does not have a zero (0) key.

It is a French model, and so among the keys it has as extras, are some very un-useful ones even for writing French. Notably the dedicated ù key... Which is used in a single word in the french language!!!

(or should I finish: apostrophe apostrophe apostrophe backspace backspace backspace period period period)