I once heard that in the 50s a NATO nation paid its aircrew flying pay on the basis of how many flying hours they achieved each month. It sounds like a good idea, fair, practical, etc....
What actually happened?
The aircrew stayed airborne as long as possible on each sortie, using diversion fuel, etc, and landing on fumes, all to maximize their flying pay. When the nation in question starting losing aircraft on the basis of engines flaming out they decided to re-examine the cost effectiveness of their policy.
As to adopting policies that may make people leave - there is a fine line to tread. On the one hand you can't be held to ransom, but on the other, to deliberately introduce a policy, or remove a current one, that will result in experienced people (who can cost several million pounds each to replace) leaving needs to questioned. Cost effectiveness is the name of the game. How many people does an unpopular policy have to force out before any savings made are outweighed by the costs of replacing those who leave....