hawk 37
It has to do with the slope of the CL / AoA curve. In a 727 it is much shallower than in an ATR. Swept wings are good for flying high and fast without having too much shock wave drag, but they are bad for flying low and slow because they "waste" some lifting ability.
If you compare swept and non-swept wings lift versus angle of attack curves you will see that for a given change in angle of attack, a 727 would have less increment in lift than an ATR.
You are in a 727 at 50 ft above the threshold at idle with too high a rate of descent and, because of the idle condition, with a steeper than usual angle of descend. You will have difficulties in arresting that rate and that angle with elevators only, as a change in pitch will not have much effect in lift, and therefore in the flight path. Besides, drag increases a lot during a pitch up at landing speed. So instead of a normal flare and landing the result can be a hard landing or even an accident.
On top of that, accelerating the engine to get the thrust you need to solve the problem can take too long, so you may be unable to avoid the plane from falling on the runway or even you could instinctively and frenetically pull the nose till the stall, only worsening things.
In an ATR, pulling up the nose can quickly change the flight path from steep to shallow. You can also increase thrust faster.