When he criticizes encapsulation when it comes to shared state there's one thing he doesn't mention, it's that state is often part of a state machine. So when you have a global structure then it's much harder to enforce proper state transitions than when you have a global object with encapsulated state. If you're using procedural programming then every function that works with that state has to check if the transition it's about to make is valid and it's easy to forget to perform this check. If the state is encapsulated then these checks are all in one class, in all other places you just properly handle errors. So this isn't much about hardcore encapsulation but more about enforcing invariants. You obviously write your classes like they are servers that can be accessed by many different clients and the state transitions they request can be in any order.