I have serious hesitation opening up this argument but...
Excerpts from mail: 13-Nov-91 Re: /alternative John C
Klensin(_at_)INFOODS(_dot_)M (1561)
Alternate hypothesis: regardless of the transport mechanism, fancy
mail really isn't important enough for the vast majority of messages to
be worth the marginal trouble.
Maybe so, maybe not. I don't find your analogy compelling, however.
People include non-textual materials in mail a LOT. Hand-written
letters often include drawings or the equivalent of "font alterations"
which already takes us way beyond the realm of plain text. People often
send audio tapes & even video tapes via mail these days, too. All of
these are direct analogs of what can be done with multimedia mail.
My own prediction: when everyone has multimedia mail, something like 60
percent of the mail will still be "plain text". The next 30 percent, or
so, will be "rich text" -- i.e. it will use fonts, etc. Only ten
percent will use anything beyond that. However, that 10% of the
messages will generate something like 90% of the bandwidth, and will
often (though not always) be perceived as being of enormous added value
for its multimedia content. This prediction is no more than a WILD
extrapolation from the CMU/Andrew experience. (I can tell you from
direct experience, however, that when a user sends in a bug report that
includes a screen snapshot that demonstrates the problem, you REALLY
appreciate the value of multimedia mail...)