Because most people fail at reading. Not the standard "reading comprehension" insult, they just don't bother reading these things to begin with. :(
Quite a few of the long time players that I know refuse to look at the POL frontpage and these forums saying that all info should be given to them in-game, or that they can always ask me. There's also been a seemingly large increase in new/returnee players within the past 9 months who might not even know what info they missed. I can understand those players being shocked and upset, but anyone who's been around since the vote was taken has no excuse.