Because it's the equivalent of looking inside someones head and knowing what their intentions are. You see we have a mission board and mission list, but technically this is just game play mechanic for something we can't duplicate in game. In reality no-one is going to post up illegal missions like smuggling on a public mission board, or missions to attack another faction because all the police or enemy faction would have to do is to look at the mission board to find out who is working against them.
If this was the real future I wouldn't look for smuggling or illegal missions or combat missions on a mission board, I mean how silly in reality would that be.
"This is Sundarvan of the Left Hand of Darkness, we want you to go out and find some weapons for us and smuggle them back into the station for our insurrection....hang on there's somebody at the door," "Open the door this is station security, we saw your post on the public mission board so we are here to kill you!"
In other words the mission board is a poor substitute for clandestine meetings and secret missions offered to shady pilots by men in bars and other places shady pilots meet up. I would be approached by an agent or emissary of the contractor who knew my reputation and willingness to get illegal goods into places for lots of money and everything would be carried out in secret and just kept in my head, I would never put this stuff in a computer simply because someone might scan or hack it, or the police do a search of the ship and download my drive contents, which is what you want to do. Oh sure put legal public missions there for you to scan and find, running medical supplies in to fight a disease out break is no issue, I would log that on my computer, but I have this secret compartment loaded with body armour and guns that no-one knows about except me and my buyer. Oh sure if you scan the ship and detect it you know I have it, but you don't know what I am doing with it, for all you know it may before your side!
So putting an insta-know button in is just ruining some RP game play that people like to indulge in, so I am against the idea, no-one can know what's in my head, the fact we have to put everything down as a recorded mission is just a limitation of the game, not a reason to be able to find out what everyone is up to.