Sadly this type of "discrimination" occurs in many areas - take the Oxbridge/Old Boys network as an example - does having a 2:1 from Oxbridge make you better than having a 2:1 from one of the new universities? Well some would argue yes, others would argue that those candidates going to the new style uni had worked harder because they probably were there as they didn't have the entry requirements for a bigger uni... Could you then go on to say that companies doing their "Milk Run" who only use selected universities are discriminating.... well in a way yes they are, but as has been pointed out previously they are going for products that they are aware of, have probably been through themselves and know all the details about.
I hope Scroggs gets some meaningful replies and enlightens some people within the industry, as us lower down on the food chain are too paranoid about upsetting the apple cart in a small industry.