When you are creating new WSDL document with options "concrete", "SOAP or SOAP12", "Document literal" you can't choose for request,response,fault mesage type xsd:string because R2204 WS-I Basic profile. That's ok I can create without <message><part/></message> but then I must create rest my wsdl document manually.

My suggestion: maybe for simple type from schema http://www.w3.org/2001/XMLSchema automatically create <part/> in message tag with element attribute because type attribute is wrong for WS-I BP.
example:
<types>
        <xsd:schema targetNamespace="http://j2ee.netbeans.org/wsdl/Notify/java/newWSDL1">
            <xsd:import namespace="urn:uddi-org:subr_v3" schemaLocation="notify/uddi_v3subscriptionListener.xsd"/>
            <xsd:element name="newElement">
                <xsd:simpleType>
                    <xsd:restriction base="xsd:string"/>
                </xsd:simpleType>
            </xsd:element>           
        </xsd:schema>

<message name="newWSDL1OperationResponse">
        <part name="part1" element="tns:newElement"/>
</message>

For me it's problem when I'm using external schema types with in bilds most popular schemas.

I thing WSDL creator should be coherent with actual WS-I BP but I know that it has had many restrictions for Web Services.

If developer didn't know about WS-I BP because WSDL creator will make everithing:) ok allmost; that would be great.  

 R2204   A document-literal binding in a DESCRIPTION MUST refer, in each of its soapbind:body element(s), only to wsdl:part element(s) that have been defined using the element attribute.