If, in normal circumstances, we were approaching the hold and I could see no such settings, then that would make me very worried indeed.
Making a cabin insecure would be not very high on my list of concerns.
So it's -5 celsius, snowing, and the taxi ways are contaminated. Approaching the hold (assuming you know it is the hold, as you can't see forward) you decide it's up to you to make the cabin unsecure? What about de / anti icing and then setting the flaps? And what if it's a Flap 5 take-off - or whatever the lowest setting is on your particular type? Perhaps even LE only, as you're sat at the back you don't see the TE move.
I'm not saying right or wrong, I'm just saying that there's often a lot more going on. If the aircraft started to accelerate with engines stable, then yes - stand up, run around, open a door, whatever. But until that point you don't know where you are or what's going on and are second guessing the crew, procedures, TO config horn, and a whole host of other items.