why not build like this

Chris is following 'Hibernate Getting Started Guide'. Please take a look here (I took the latest 5.2):

http://docs.jboss.org/hibernate/orm/5.2/quickstart/html_single/#hibernate-gsg-tutorial-basic-test

They are saying:

The setUp method first builds a org.hibernate.boot.registry.StandardServiceRegistry instance which incorporates configuration information into a working set of Services for use by the SessionFactory. In this tutorial we defined all configuration information in hibernate.cfg.xml so there is not much interesting to see here.

Using the StandardServiceRegistry we create the org.hibernate.boot.MetadataSources which is the start point for telling Hibernate about your domain model. Again, since we defined that in hibernate.cfg.xml so there is not much interesting to see here.

org.hibernate.boot.Metadata represents the complete, partially validated view of the application domain model which the SessionFactory will be based on.

The final step in the bootstrap process is to build the SessionFactory. The SessionFactory is a thread-safe object that is instantiated once to serve the entire application.

The SessionFactory acts as a factory for org.hibernate.Session instances, which should be thought of as a corollary to a "unit of work".

And the Java Code there:

protected void setUp() throws Exception {
    // A SessionFactory is set up once for an application!
    final StandardServiceRegistry registry = new StandardServiceRegistryBuilder()
            .configure() // configures settings from hibernate.cfg.xml
            .build();
    try {
        sessionFactory = new MetadataSources( registry ).buildMetadata().buildSessionFactory();
    }
    catch (Exception e) {
        // The registry would be destroyed by the SessionFactory, but we had trouble building the SessionFactory
        // so destroy it manually.
        StandardServiceRegistryBuilder.destroy( registry );
    }
}

P.S. Your code will probably work, I guess. I found examples at http://www.tutorialspoint.com/hibernate/hibernate_examples.htm for example. But I think we should follow the pattern presented in documentation, because all additional classes like StandardRegistryBuider are important. And it is always a good policy to follow documentation, right ? :)