Not true. Computers treat the two cases as separate characters
because
there is no mechanism of having different versions of the same
character. However, humans treat the two cases as two forms of the
same character.
For a small subset of Western European languages and subject to all sorts
of caveats. Perhaps we should ask the same of say accented v unaccented
letters (where the policy of being the same is very language dependant)
or about languages of the rest of the world (the ones actually used by
far more people than English variants).
The question then reduces to: should the yum interface be designed
to
be comfortable for a computer to interface with, or should the yum
interface be comfortable for a human to interface with.
That question has no bearing on case sensitivity of yum if you bother to
think about it a bit more. A "did you mean" matching interface is quite
different to internal case sensitivity.
Alan