It’s because Americans are a pragmatic people.
And there is no shame in that.
“What’s it for?” and “What will it do?” — for example — are questions any one of us will ask when confronted by something new.
For Occupy Wall Street, clearly the “What’s it for?” is to tell those in power that the end of their free reign is coming to an end. Popular resentment has boiled over into action now.
It’s the “What will it do?” question that nags.
How is change expected to come about?
Every politician and financier jumping on a jet and fleeing the country?
Politicians finally finding the backbone they’ve not had since the 1960s and rolling back the deregulation that’s been the trend since Reagan’s 80s?
Just don’t tell us something is wrong. We all know something is wrong. I have three damn years of screaming that’s something’s wrong and several hundred blog posts pointing to all that.
What’s next? What’s the end? What’s the solution or solutions?
If you’re going to publish a list detailing wrongs, what’s next?
“What will it do?”
I don’t think that’s either too much to ask nor a ridiculous question.
Mike Cane’s xBlog 
It’s very perceptive of you to identify this as the reason Occupy Wall Street is so confusing to many people.
It is a reasonable question to ask what the objective is.
However, in this case, I’m afraid you won’t soon get an answer, and this for two reasons:
1) The participants seem to be a very diverse group and while they may share their outrage that something is terribly wrong, it’s probably unlikely they would reach a consensus on what should happen to make things better. Typically, it works the other way ’round; once you identify the desired course of action, people come together and rally around your cause (the action or objective you want to achieve).
2) Protesters usually demonstrate for causes like passing a law, repealing a law, stopping a war, obtaining a pardon, receiving better wages or health benefits, closing a business/factory (or keeping it open) and so on. In the case of Occupy Wall Street, it’s not just one thing that is wrong that causes all these problems people are protesting, it’s a whole slew of things, and the issues are so complex that it’s not obvious even to the experts how to fix it. The changes are too fundamental.
So the problem boils down to the fact that people agree something is wrong, but the problem is so intractable that nobody really knows how to fix it in a practical way.