Hi
After going through the various reactions and feedback to the original post, I feel the original intention of the company was to lay off these people. Since they have been working for the company for 15 long years, the company did not want to be seen as one that does not value its employees. What does it do then? It asks HR to take action.
HR draws a conclusion they are unproductive or non performing employees of the company. So what does it do? instead of finding the root cause of the problem, it just moves them out to the different department / section / job role (most probably without any discussion) cuz it wants productivity or so it has projected. The bottom line being, moving these people to roles that is either beneath their skills or to humiliate them. The people either felt humiliated or cud not cope with new role. Hence some of them chose to quit to end the humiliation and the others chose to adjust to the new situation either due to desperation (if they are aged then chances of getting another job in times of recession is bleak) The end result, Company through HR achieves its goal.