From what I've seen, fresh developer grads expect to take entry-level positions. Fresh MBA grads generally don't; they expect to be listened to as high-level advisors or managers. That is not an unreasonable expectation, in that their programs train them for that.

Another way to look at it: It's well-known that large-company execs often adapt poorly to working at startups, partly because they are used to having other people around to do the actual work. An MBA trains people for that sort of large-company position, so it's unsurprising that people fresh out of MBA programs would have the same issues.