I don't like the sound of an elite clique forming that excludes those who are unable to pay or for some reason can't participate in that clique, and this is prevented from roles such as CEOs/upper management.
The people you meet at conferences are not likely to be highly placed, and you will not have a particularly strong bond with them.
Spend 2 years in a highly-ranked MBA program, though, and you will develop deep, long-lasting bonds with people, many of whom will end up in important positions.
It's the same sort of deep connection you get from being, say, an early participant at an important company. The PayPal Mafia [1] are important partly because they are smart individuals, and partly because they're part of a well-connected network.
I hear you also get a similar effect from incubator programs like Y Combinator: it builds bonds that last.
However, I also appreciate how valuable a good network is. People are social animals, and good networks allow you to cut through a lot of bullshit.
When I'm hiring, for example, the first place I always go to is my network. Placing ads is such an arduous and chancy process. If I can hire somebody who has strong recommendations from people I know, it's much easier and much more likely to work out well. Those people have collected information over time on things I can't possibly discover in an interview. And the social relationships provide a context that make the relationship more solid than one brokered via Craigslist.