I love stretch goals and I see nothing wrong with the communication.
Of course it is a general problem that people don't really see expenses like taxes, kickstarter and amazon costs, production costs of boxes and prices, costs for programs and engines, hardware, rent, wages and social costs and even communications on the forums costs time and thus money. On the other hand, if people knew exactly how much of their money will go to such things they maybe will pay even less, because they want to fund the development directly and not collateral-costs