most of the reason might be because of the manager. but we still need to take other factors that cause people to leave.

1) Marriage. to be closer to family.
2) structure efficiency.
3) Seeking new challenge.
4) Promotion.

If you working for big company like MNC, you still have the choice to move to other group if you dont like your manager...

Just my 2 colon...

if you working for a company. would you stick to the same position for many years? As time goes on people need to climb the ladder.

The manager wont hold a person if he feel he cant contribute to the team n not happy to work with the team. It just a disaster. There is always HR that you can consult if the manager dont want to release you...