The FD isn't a no-go item. With the exception of a handful of procedures, its use is at the discretion of the PF. If the PF says FD off, then FD off. Particularly in a stall, where the FD will be commanding the exact opposite of what needs to be done (se AF447) it's a useless instrment. Why expend the extra brain power to look behind the FD when you can just turn it off?