As mere SLF I'm more than disappointed by the lack of self reflection and 'wouldn't have happened to me' arrogance of some posting on this thread. This mindset makes an unnecessary hole in one of those slices of Swiss cheese.
As an engineer working with safety system reliability I'm puzzled by the arrangement of the two stab trim cutout switches on the Max. if I understand the schematic in # 3882 correctly the Main Stab Trim Cutout switch does everything and the Backup simply provides a set of series contacts for a subset of the Main switch functions.
Given that series contacts didn't appear to be necessary in previous 737 systems it might be concluded that the Backup switch is superfluous other than as a piece of window dressing to make the switch arrangement look like it always used to. This seems like a potential error trap for a pilot expecting the functionality of previous 737s.