When Notch put Minecraft up for sale in it's infancy, he said, "Buy this version and your money will allow me to continue development, but you will get the game right now
even though it's rough around the edges and has issues."
I am fine with that, and I did buy Minecraft, and it's a great game.
"Fund our project or we won't make it" is just wrong on so many levels. I don't want the trinkets you promise with higher donations, I want a game to try when I put up the cash, even if it's completely bug ridden. If you don't have enough assets to at least give the backers something when the pony up their dollars, maybe you need to rethink your business model.
How much of the donation dollars are being diverted from development in order to fund the "trinkets"? That should be funneled into development as that's the goal, no?
Some of these companies are even spending advertising dollars to promote their Kickstarter campaigns.