rpc/literal

In this article:

http://msdn.microsoft.com/library/default.asp?url=3D/library/en-us/dnsoap=
/
html/understandsoap.asp

the author makes the quote, "Rpc/literal [is] possible but [it doesn't]
make much sense"

Can someone expand on why that is the case? I have a vendor who
currently is exposing an rpc/literal Web service that I obviously can't
generate proxy classes from in .NET and I am trying to make a case to
them as to why it would be beneficial to move to Document/literal going
forward.

Thanks,

Paul