The world is not black and white but unfortunately you'll be amazed how many dumb asses are involved in recruitment.
Some article on TSR remarked how a recruiting manager thought a 2:2 was a made up degree classification.
The problem is there are just too many applicants chasing too few jobs that in order to cut down their time, they stipulate a cut-off of a 2:1, regardless of where it's from, rather like the government's scheme to get people to teach, by offering greater incentives to those with a 1st (even from McDonalds) than a 2:1 from MIT.
Likewise, to those in the know, you can't get much better than maths at Warwick in the UK but for the general public, some recruiting managers would prefer history from Oxford for a risk job within a bank because it's Oxbridge.
The BBC is particularly guilty of this. Take this article for instance:
http://www.bbc.co.uk/news/education-22447965Despite Imperial coming top for Civil Engineering, the headline still states Oxbridge being top in 7 "key" subjects, these being English language and literature, philosophy, modern languages, geography, maths, linguistics and history.
IMO, Civil Engineering is certainly more "key" than philosophy, geography and history, It's possibly even more "key" than english langauge, literature, modern languages and linguistics.