Engineering has always been a put up or shut up kind of field. I've seen people with very little education who are some of the most respected programmers in their field and I've seen people who barely graduated from State U making 175K leading huge departments. It's kind of hard to do that with say, investment banking. How is an undergrad supposed to prove they are an amazing investment banker? What kind of portfolio do you assemble for that?

Part of the issue here is not just the name on the degree, but that they want people that are homogenous and from that Harvard/Yale milieu so they can chat up other bankers who also graduated from Ivy League schools.