That’s an absurd statement. I do not need to open the power switch on my table saw to understand and recognize that when I turn it off the blade stops spinning.
Even if I were unable to directly view the blade I could see that stock passed across it is not cut.
Even if I didn’t have a table saw I could read the news stories about law enforcement complaints that turning the power button to the off position stops the saw from spinning and craftsman is unwilling to offer a bypass to the switch citing safety concerns and form a cohesive rational understanding that the control does what it says on the tin.