Do you really think laymen understand risk, though? Casinos make billions of dollars each year off people who can't correctly model risk even after risking, and losing, large sums of money. Of course, VCs wouldn't put their money on black at the Roulette table--but VCs (and stock-brokers, and investment-bankers) model risk for a living, whereas the median layman micro-investor will have given their one or two investments maybe five cumulative minutes of thought in their lifetime.
To put it another way: there's a sucker born every minute--but no-one stays a sucker for very long, once they've been burned. This means that, when there is friction to investment, the suckers will slowly drain from the pool until only the sharks are left; whereas, when fiction is low, each sucker leaving the game will be replaced by a new sucker joining in, fresh and naive. When 90% of your revenue comes from people who have never invested in anything before, you can build your business model on the mob's irrational overconfidence in your ability to deliver.