How much of this kind of thing is a by-product of marketers as well? I've seen more then a few events where the people who actually did the development were excluded to accommodate business partners and clients. It's not that marketing necessarily wants to exclude developers, but space and resources are limited, and socializing is an important tool in the marketer tool kit. Not that I condone this (having been on both sides of this equation), but it does speak to the shifting sands of prioritizing the goals of these kinds of events (is it a company celebration to thank employees, or a marketing event?)
FWIW that wasn't my experience for the past two IOs. I mostly met real developers and entrepreneurs, even at the after-parties. To be sure, the lure of free phones makes for a few fanboys and denies some deserving developers. But it was overwhelmingly a developer conference and the sessions certainly reflected that.
In the past ... the PR people used to actually communicate to us that the event was just as much a celebration to thank employees as promoting the company.
