You gave me the impression, in your article, that I would not be able to find failed projects by searching on Kickstarter unless I had been following them and knew their exact names. But this is not true. Your example, Instaprint, illustrates this. I need only to search for (for example) "instagram" or "print photo" and the failed project turns up. I don't need to know that there was a project called "Instaprint". Kickstarter makes it easy for me to find failed projects in any area that I am interested in. This puts the lie to your main point, that they are making it hard for entrepreneurs by hiding information about unfunded projects. That they selectively ban robots from indexing unfunded projects is interesting, but this is not the kind of thing I would use Google for. If I wanted to find out the fate of various types of projects on Kickstarter, I would naturally search on Kickstarter. And this seems to work perfectly.
I really have no idea why you would expect unfunded projects to appear in the "Discover" interface. The whole point of it is to engage donors - why on earth would I want to look at projects that didn't happen, as a donor?