It's a feature of capitalism. They're worried you might be working two jobs, or might make/join a startup and compete with them, or generally not feel enslaved

It's a feature of capitalism. They're worried you might be working two jobs, or might make/join a startup and compete with them, or generally not feel enslaved to your employer. At at the very top, at the big shareholder level, they don't want the middle class having too much freedom, because they do pose a potential threat to them.