Also, quite literally, people (both management and other engineers) often don't fully think through the consequences of systems that have neither enough automat

Also, quite literally, people (both management and other engineers) often don't fully think through the consequences of systems that have neither enough automatic failover nor enough staffing by non-distracted humans, and build systems assuming that it will be fine. It's probably better to suffer an unexpected outage now than in the future when your company is bigger.