Orthogonal
Member
Some people like to Co-Op after beating a boss and having to PvP while waiting to be summoned was obnoxious especially when the immunity to another invasion is shorter than the time it takes to get summoned. This way people who want to PvP can and the people who wanna Co-Op don't get swords in holes that were meant as an exit, not an entrance.
You can prevent invasions by going into the boss chamber. It can get rather boring however, just staring at the walls for someone to summon you.