This is not just a Kickstarter problem. This sort of thinking is rampant in the corporate world, and in the government. Executives are just horrible at estimation of cost or difficulty of projects. Many of them think up an idea and then assume everyone else will make it work on time and on budget. They think it's just software, and how hard can that be? Or it's just a bridge, we've done so many bridges before, so how hard can that be? I see so many times that deadlines flow down from above; the product must be ready by the time of the trade show, or it's been sold to a customer already.
The same thinking that applies to having just a minor modification to an existing product is still in place for products that are very new or novel, or products using new parts or systems.
So draw up the system diagram on the white board. It looks so simple. The trap is then thinking that it's all understood and we're ready to go.
Some times I think it's because the executives mistakenly think they're a part of the team, or that the workers are all just a highly motivated as they are. It's not true, these are two distinct groups. Execs have no clue whatsoever about how things work at their companies, even if they used to be mere workers in the past. They've been removed from reality for so long they don't remember it. They very often come from a world that knows only about sales and financing. They'll get an extra million dollar payout if the project succeeds, but the workers may get only a thousand dollars in bonus.