WCF/WF - WCF : username/password authentication with basicHttpBinding

WCF doesn't support username/password authentication with basicHttpBinding when security mode is "message". In fact one has to use "TransportWithMessageCredentials" to be able to use it. what could bethe reason for it?
Also, on http based bindings, for any form of client credential type other than "windows", WCF requires the service to provide a certificate. Why?

IIS or WAS hosted services do have BASIC authentication working in BasicHttpBinding mode. You need switching to SSL (Transport security mode) and rely on services provided by host. I implemented that and it works perfectly. Here is client-side configuration:

<basicHttpBinding>

    …

    <security mode="Transport">

       <transport clientCredentialType="Basic" proxyCredentialType="None"

          realm="" />

    </security>

    …

</basicHttpBinding>

 

MSDN provides nice HowTo. Look at http://msdn.microsoft.com/en-us/library/ff649647.aspx