As others have mentioned... Tim Schafer (and Ron Gilbert) have a hell of a track record. They have an incredibly loyal fan base, and a series of past successes. The reason why Tim Schafer was able to raise $1M in less than 24 hours was because A) he's Tim of Legend and B) there is a market hungry for adventure games like the ones Tim and Ron made.
Markus Perrson (Notch) had something tangible to show and for people to play before he started accepting payments for Minecraft. He was effectively a nobody in the industry, but he had something playable.
Even Tarn Adams (Toady One) had releases of Dwarf Fortress before he accepted and attempted to live off of donations. Again, a nobody in the industry, but he had something playable.
No Time to Explain? Had a flash game before they did a KickStarter project.
Project Zomboid? They had demo videos to show.
It's something I used to tell my boss -- quit trying to sell stuff to customers you refuse to let any of us developers start actual work on. Let us build a good prototype then let's go sell it.
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Is this a first? Can anyone show an example where there was funding behind something that didn't even have anything to show?