With such things, it's going to be the pitch that sells the game. However, the pitch is always going to implicitly include things such as star power (ie. popularity of the people pitching the idea) alongside experience. "Ideas guys" are going to need an amazing pitch to pull in decent coin if they don't have past successes to point to.
I don't think there is necessarily any idealism associated with it directly, ie. that it is out there to support the little guy, the people with the best ideas, or the coolest concepts. I think any such idealism is more an occasionally fortunate side effect that comes about from people supporting what they *want* to see, rather than anything deliberate. For example, if there is a good idea out there and a team that has established that they can do it (through past successes), but they need the funding, and they can't find a publisher who gives enough of a damn to green light it, it gives those developers another way to source the funds without signing over 95% of the profits and taking the funds as an advance (ie. loan). Everyone wins, except the publisher, who gets a rude shock, which they deserved.
However, just as easily, a less-well-known developer might have the best idea in the world, a cool demo, and the skills to pull it off, but if not enough people know about it, the target may not be met.
And again, just as easily, someone with high exposure might bring very little to the table, apart from their name, and get funded to an extent far greater than the more "worthy" project above.
So, again, I don't think there is necessarily any direct idealism attached to it, apart from being a neat way for a popular concept to get funded, rather than begging to a publisher and hoping for a break (or selling your soul for it, and by "soul" I mean all of your assets and most of your profit). It also lets "the people" decide if they'd be willing fund something, rather than a publisher or investor being the bottleneck. Having said that, that sounds a little idealistic, so perhaps I have contradicted myself!