Let's not forget that the Kickstarter phenomena is still is its' infancy and everything seems like nothing but sunshine and butterflies. THE singlemost frequent problem in game development is missed deadlines and subsequent delays.
The Kickstarter method is even worse when it comes to renegotiating contracts than regular publishers because instead of dealing with a single entity you need to ask thousands of backers for more money (or maybe even start a New Kickstarter campaign).
If developers in general had been capable of estimating the cost of a project (both in terms of time and expenses) in the first place, there would be no need for Kickstarter.
I like the Kickstarter idea and I've already backed several projects but I fear that before long we'll start seeing failed projects where the devs couldn't live up to the initial estimates and are forced to drop the project due to lack of funding.
The situation is different. Published projects have to seduce a future customer base. But even with that, very often, games are released in a beta state or even worse. The first sales are to keep the project rolling and fund the necessary patches.
KS projects are in a far better situation: they have already seduced their customer base. As stated, published games, even as they have to seduce a future customer, are released in a non finished state.
How could KS projects have to deliver on the expectations when published games do not have to, to sell, and can go round panhandling after release day to promise better features if the game sells well? Buy the game, and we'll finish it.
All what KS projects have to do is provide a minimal version of the game, that installs. There is no other expectation. Because that is the expectation on published games.
As every buyer is registered in a data base, contacting themselves to sell them a new round of funding is very easy with current means. And it will work the same as for published games: if you want the game to be finished, provide new funds.