The employees aren't the decision-makers running the show, man. Come on.
People don't WANT to job-hop. This is a myth perpetuated by the disconnected.
They are FORCED to job-hop due to bad bosses that aren't good leaders and don't leverage their staffs unique abilities. Interviewing sucks. It's a massive time suck too. Changing jobs sucks.
The book The Talent Advantage does a good job laying it all out, take a read.