That's why Apple lets Enterprise users delay updates (Yes, even App Updates) for custom groups within the workgroup. It's all about the fact, that iOS itself is designed to be as easy and safe to use as possible. Enterprise functionality comes only when Adopting to the Enterprise Management program Apple offers for companys. (And its functioning really good.) And for all enterprise users that don't have their company setting up that MDM solution, you can just turn off Auto-Updates within the settings.Even so, the fact that enterprise users don’t care about update that much already tells something, and the main reason why Microsoft still gives enterprise user the ability to delay OS update longer than usual. In a mission critical environment, stability outweighs everything else. Here is an example: Sydney train computer system was undergoing a system upgrade one Friday night, but it went wrong and millions of commuters at Saturday morning were crowding key stations waiting for the train to come. You could argue their upgrade incident does not happen very often, but still, upgrade breaks things. Just like how developer deserts customers, customers also desert developers. Welcome to the free world.
And just a short reminder that old Windows System software is a big security failure (Example: WannaCry)