Because it can be hard to deduce from the message - especially as
messages may be composed of many pieces from other places using
SOAP's
modular extensibility mechanism (headers). In a sense this is similar
to that a media type can be hard to guess based on the entity alone.
then add that to the SOAP payload that gets passed in the HTTP
entity body. don't penalize HTTP for SOAP's design deficiencies.
It is not for the benefit of SOAP - it is for the benefit of HTTP which
is why it is expressed in a manner that is digestible by HTTP. Your
argument could equally well be applied to media types so does that mean
that you feel the same way about that?
Henrik