This is exactly the "developer-centric" mindset that is, frankly, misguided.
Sure, I would rather deal with an outage during business hours, but that means that many of my Customers are also dealing with an outage. If the outage were at 4 AM, most of my Customers would be asleep, and wouldn't even notice the outage.
I'm sure that's the plan. But if you reallyreallyreally need faultless 24/7 you're looking for something akin to "NASA as a service", and I assume that such a service wouldn't be able to invoice using something as pedestrian as a credit card.
You don't need to make your developers work a 24 hour cycle to do off hours maintenance. You plan ahead, give the team doing the update the day off before and give them a reasonable window to work with.
Maybe I'm wrong but if a deployment goes wrong at peak hours it's going to amount to a lot more lost money for the customer than it will if a deployment goes wrong at off hours. If you cost your customers money with an outage they're not going to care that you scheduled a developer-centric maintenance window.
Sure, I would rather deal with an outage during business hours, but that means that many of my Customers are also dealing with an outage. If the outage were at 4 AM, most of my Customers would be asleep, and wouldn't even notice the outage.