User blog comment:Master Sima Yi/Assassinews 05-08-'14 – Assassin's Creed: Rogue announced/@comment-5019018-20140911221008/@comment-1379800-20140913073200

Well the idea behind AC is that you're recreating actual events. The closer you are to what really happened, the more synchronized you are to your ancestor's memories. It's not like you get punished for not 100%-ing a mission. Beside, the actual gameplay of AC games is so easy that they need to load side-objectives to make the game challenging.