I think the big point here is that you have no way of knowing if a kickstarter is dodgy or not. And it appears that even the people running the campaigns don't know a lot of the time. By backing a project you are essentially committing your money to nearly blind faith. Without having gone through a product life cycle from start to finish and had it be successful you have no idea how much work it is going to be and how many different fields you need to touch.
When a big company says they are going to make something cool, it's usually (I know, not always) safe to do things like preorder because at the time they announce a product they are most likely already done with the design and have the production rolling. There have been whole departments of people doing design, research, marketing, consumer focus groups, production engineering, etc. before anyone outside the company knows anything substantial about it. Kickstarters are usually just some guy with an idea. It might be a really cool idea, and there might be a prototype, but that's not yet a production item. You have no guarantee anything will work and you can't just go get a refund if it doesn't.
You can't just say "don't donate to the dodgy ones" since every kickstarter is "dodgy" until they actually ship something.