Why would I want S/MIME?

[Robert J. Hansen]

> I understand what S/MIME is and that it's probably the easiest crypto
> solution for most email users. But why would someone comfortable with
> GnuPG use it?

There's a subtle point here.  The question isn't whether you're comfortable with GnuPG; the question is whether the people you want to send email to are comfortable with GnuPG.
 
I use S/MIME literally daily at work.  My co-workers like S/MIME because it's close to an "it just works" solution.  Few of my co-workers have been willing to learn GnuPG.