I think the majority of this is due to people not fully understand what their kickstarter money was for.
When you give money to a kickstarter project, you are doing nothing more then being a nice person who wants to donate a few bucks to an idea in the hopes that idea will take off an be a real tangible thing one day.
While I do think it is shitty, and possibly unethical, for someone to take a kickstarter idea and sell it off to a huge company for millions/billions of dollars... it is entirely within their right to do it, and they owe you absolutely nothing for it.
This kind of stuff is exactly the reason why I have not/will not ever give any money to anything on kickstarter. I don't like the idea of giving money for something that I might never get anything in return for.
BUT, if you are the kind of person who does give people money on kickstarter, and you seriously never expected that something like this would happen. You are delusional and naive.