VC's have to judge if there's a market and Kickstarter helps with that. But VC's also try to judge whether the founders have the ability to succeed, whether their business plan (costs vs. revenues) are sensible, etc. How does one do that through Kickstarter? I'm sure you'll agree more than 50% of the people who've funded the project on Kickstarter didn't even bother to figure out whether the startup is set up to succeed. (For additional evidence, see "Diaspora")
Btw, when you say Kickstarter campaigns can be 100x smaller, I'm assuming you meant to exclude ones raising upwards of $3.8 million right?