This is completely wrong. First it makes the assumption people are somewhat experienced with how game development works and second it takes responsibility away from the devs in setting a release date.True, however, if you know that the dev team consists out of 5 persons and they want to create a game the size of Skyrim within 2 years then you need to learn a lesson.
People need to stop putting release dates on Kickstarter that are not realistic. This is the cause of the discontent (particularly as people pay for that expectation) , not that they're not patient.
Exanima is clearly a good product and worth the continued wait, but there's no sign of Sui Generis yet and I'd be pretty pissed too if I'd backed Kickstarter and expected actual delivery before now.
Using an old 'what if' here, but if I had lots of time for games at expected release, but then had none when it eventually arrives, I'd also be not happy (especially if Sui Generis turns out as well as it looks)!