I'm sorry, I don't understand. You've told us why you yourself don't need to set a fleet 12 hours in advance, but why exactly do you want that removed as an option to others?
I use it. For example; If I'm going out for a while and not going to be able to check my account, I put my ships into a fake attack fleet set in prelaunch, that way I have (12 + 9 + 9 = 30) hours of time to not worry about someone bjorking all my ships