I think that limitation of scope is very intentional on their part. Tracking the actual progress of these projects could be a very intensive and diverse undertaking. I don't think Kickstarter calls a project successful, I think they call a fundraising successful.
It isn't a mistake: the project is the fundraising itself, not the business/product that is being funded. People are making funding pledges that only turn into actual contributions if the fundraising project meets its target. If the target is not met, no funding happens, and the project is not successful.