Expectations should be lower as far as responsiveness or even availability, for someone who is not actually on call. The load (and expectation) is also not even

Expectations should be lower as far as responsiveness or even availability, for someone who is not actually on call. The load (and expectation) is also not evenly distributed: IME senior and staff/principal-level engineers (and managers) tend to get paged in when off-call much more frequently, for obvious reasons. It's more likely to be "I need someone who knows XYZ", not "I need absolutely EVERYONE" https://www.youtube.com/watch?v=74BzSTQCl_c https://www.youtube.com/watch?v=74BzSTQCl_c or "I need a random additional pair of competent hands". Also, IME it's been relatively rare for issues outside of business hours to require calling in people who aren't really on call. I think the article is pointing out that it can be the right thing, not that it's necessarily a common scenario. And during business hours, being pulled away from your other work to help handle an incident is obviously a much easier pill to swallow.