Agreed. Hardware projects are too high-risk for a model like Kickstarter's, and it's difficult for crowdfunders to be fully informed about that risk when even the makers are often inexperienced.
Worse, they're all or nothing. If one of the major videogame projects runs out of funds, they can still release a beta version or even open source it. If someone is unable to finish a book, they can still send you the latest draft. When hardware projects fail, they probably can't ship anything.