Kickstarter handle the funding end of things. When a project is funded they did their bit. People contributing know they are getting promises that may not turn out. They're not buying stuff. They are getting enjoyment out of being a part of something. Celebrating when a project succeeds. Getting disappointed when it doesn't.
Maybe the hype will end and this'll all blow over. Maybe Kickstarter is here to stay. Either way, it's obviously not malicious.