Once I've backed something I want a button I can press which reads "Never send me any more emails until the game is actually completely ready, finished, and I can play the final version. I do not want to help you test it. I do not wish to spend time in your forums giving you feedback. I wish to play the finished, polished, tested version, when it is done. That is all."
I can live with one update per month, telling me that a project is still on track. But I really don't need to know every detail of how the game is put together, complete with videos of developers and artists arguing with each other over what shade of teal to make the bad guy's epaulets.