There seem to be two main ways in which organisations treat their “deserters” (i.e. people who choose to leave). The first is by ignoring them, and the second by harrassing them!
One wonders why.
After all, if it seems that unfair to you that the guy chose to leave, you could always tell him to leave immediately, and not serve his notice period. You could always sign fixed term contracts with people. You could always promise life-time employment to people. You could always listen a bit more, care a bit more, think about your people a bit more, talk to them a bit more…while they are there.
Why the whiplash when they decide to leave?