B757's Flap 30 (Full Flap) speed is in round figures 162 Kts.
Makes it D---m difficult in turbulance to take the full flap in time to be on speed (Vref +) and spooled up by 500 ft.
Unfortunatly the new QAR systems tell the management each time you are not, with often a visit to your boss.
So it is easier to slow down slightly earlier and hence avoid the interview.
Human nature I'm afraid.
+ whoever decided on 180/160 seems to have not understood a/c performance. (Note we SHOULD be configed spooled up and on speed by 1000')