Everything happens for a reason. The job hopping trend didn't begin in a vacuum. Your basic employee today has as much loyalty to the company as the company has for him/her. If profits go down, then lay off 500 people and hire back other people "as needed." A job opens up at the competition, apply for it and take as many clients as you can with you.
Employees and companies today have to be nimble. I remain amazed at the number of people who continue to harbor bitterness over getting fired or a prized employee leaving to go over and work for the competition.
All of this isn't nice, but it's the way the world works.
It seems to work in Japan.