I think what made a lot of people mad is they gave a decisive date and then delayed at the last moment. I've actually read a few people say the exact thing I planned on doing when it released. I got off work and cleared my night of all activities and had the next day off, so I was pretty excited and cleared a day and a half of stuff just to play. I didnt know it was actually delayed for a few days because I figured they would update the original KSP Loading post like they did when they announced the release date and kept checking that post.
In my opinion I think it's best to leave the date open, but announce the release. If they hadn't given an exact date and said the update would release near the end of March or beginning of April, that would've been fine. I would've just kept looking for news on the release near this time. We've all pretty much learned basic rocket science and engineering to play this game, that's a staple to how great of a game it is. So I guess that just adds to it as well. My PC(toaster attached to a hamster wheel) runs the game the worst out of all of my systems and I own 3 copies of the game, so it just sucks that I've had to choose between performance and quality. But that guy who compared it to a shuttle launch being delayed is a genius and made me less angry.
