I completely agree -- and this is why I think the ability to fall back to text
for things like DTDs offers no real advantages for any significant group.
I agree with this. however, another potential advantage comes to mind.
If a body part is labelled "text/something" the MUA can convert the text
to the local format when saving the file - e.g. newline delimited
for UNIX, CR-delimited for Mac, fixed length 80 character ebcdic records
for ancient IBM systems :). The MUA can do this without having specific
knowledge of the content-type.
if the type is labelled "application/something" such a conversion
would not be appropriate unless the MUA had specific knowledge
of the content-type.
Keith