Angle brackets are for plumbers?

Clemens Vasters writes:

XML is ugly and angle brackets are for plumbers. Unless you have a good reason to do so, you shouldn’t have to look at WSDL. [...]

interface IHello
      string SayHello(string name);

The programming model here is very similar to the Java RPC mechanism I am responsible for at work (similar to RMI, but with added service-oriented goodness). So this has me wondering, if you don't want to look at the XML, how does it matter whether the serialization format is XML, Java object serialization, something .NETish, or IIOP?

One of the benefits of Web Services should be that the data format (XML) and protocol (HTTP) are relatively human-readable, making it easier to debug when things go wrong (as they always do, eventually). But if we don't look at the XML (especially if it isn't really XML), and use alternatives to HTTP, what is the point? And where did the "web" in "web services" go?

It's good to be familiar with your plumbing, even if you do need to call a plumber to solve the more serious problems.