xml-rpc was a classic Winer format and like RSS it shared the same limited interest in cleaning up oversights. Not handling unicode was simply lazy - the support was there in XML so it took effort to disable a native feature. Similarly, date encoding is a solved problem for almost all applications: use ISO 8601.
This is not to say that there are areas where complexity will creep in or that some people haven't learned from the failure of SOAP (or CORBA before it) but simply that for the vast majority of cases the problems just aren't that hard unless we choose to make them hard.
This is not to say that there are areas where complexity will creep in or that some people haven't learned from the failure of SOAP (or CORBA before it) but simply that for the vast majority of cases the problems just aren't that hard unless we choose to make them hard.