When you back a Kickstarter project, you accept the (diclosed) risk that you will not get anything for your money if the project fails. This is the nature of Kickstarter. Otherwise people would just do Amazon preorders like everyone else.

If you don't like this, don't back Kickstarter projects. It doesn't matter that you believe Kickstarter is a shop - you are wrong and the expectations you invent and project onto an organization do not and should not give it legal obligations.