Triggering demand disconnection randomly is saying "we should provide consumers a service including deliberate random blackouts". That's OK in contexts like Netflix where the downstream systems are supposed to be able to be resilient to faults and failures are comparatively low-stakes anyway. But almost all grid consumers aren't resilient to power loss (would your house continue to be fully functional without noticeable ill effects if power to it went out? Mine wouldn't...) and even for industrial scale consumers who do have generators the costs of finding out in a deliberate blackout that their generator was faulty could be anything from expensive to life-threatening.