Sometime people have been in an organisation
for so long that they just can't go anywhere else.
They are often unhappy with the company and want it to go back the way it was, they stuck perhaps because of their pension, or they waited too long in their job to move on that they do not appeal to the external market.
Sometime, even worse, they seem to haves lots of technical, organisational knowledge that they seem to hold the company to ransom and you might be apprehensive to do anything that risks losing that knowledge.
These individuals can be incredibly valuable with great strengths but they need help understanding that the world around them has changed and they need to adapt.
It is about reminding people that they have choices and they can always do things to make them happier; in this situation an honest open and upfront conversation would help