I think Kickstarter is fully focused on creative projects that do actually create things. Each project has to have a clear end point and well-defined creation. It definitely isn't made to clear out old inventory -- so in that sense, it isn't a store, but for those of us that need resources and scale to manufacture a product, it is hugely important, and a lot of their focus.
I do think there are a lot of ideas like categorization and tiering that could help people better understand Kickstarter, and I think they'll continue to refine the concept, of course.
I think that tiering may help, though I don't have the variety of experience to suggest a set of tiers, and I suspect KS devs don't either. I would suggest to Kickstarter that, now that they have a few years' worth of data, mine it and figure out those tiers. Also, start actively going through failed projects and figuring out why they failed, and release that information to the public: you have inertia now; telling people that projects fail after funding is not going to stop them from contributing to ideas they're enthusiastic about.