Taking away PS is a Pandora's box the company doesn't want to open. When you roll it into rates, it goes unseen. However, keep it separate and have that carrot (on 14FEB) and people see it as a reward for helping the company. Take away that reward and what is the incentive to single-engine taxi, wait to turn on the APU or hurry to turn it off, etc... My guess is it wouldn't take long for the company to see impact of getting rid of PS.

Keep PS decoupled from pay. Don't touch PS, for the benefit of the employees and the company.