Diaeresis vs. umlaut (was: Re: Standaridized variation sequences for the Desert alphabet?)

Philippe Verdy wrote:

> But Unicode just prefered to keep the roundtrip compatiblity with
> earlier 8-bit encodings (including existing ISO 8859 and DIN
> standards) so that "ü" in German and French also have the same
> canonical decomposition even if the diacritic is a diaeresis in French
> and an umlaut in German, with different semantics and origins.

Was this only about compatibility, or perhaps also that the two signs
look identical and that disunifying them would have caused endless
confusion and misuse among users?

--
Doug Ewell | Thornton, CO, US | ewellic.org