As a seasoned engineer, I could not agree more with the justifications you provide.
As a business owner who's customers are actively engaged with my staff who need servers and resources to be available during the day when, you know, my CUSTOMERS are awake, your recommendation for outage windows would be completely ignored.
You schedule outages around the people who pay the bills, not the people who don't.
The plan is to never have an outage. Instead be scheduling maintenance that should, at worst, result in some backed up queues or non-functional admin functions.
Building a system for graceful degradation costs time and money.
As a business owner who's customers are actively engaged with my staff who need servers and resources to be available during the day when, you know, my CUSTOMERS are awake, your recommendation for outage windows would be completely ignored.
You schedule outages around the people who pay the bills, not the people who don't.