It is like a reverse market regulation against workers that are bringing the productivity and skills to the company.
Company: "Hey come here and build us this thing that makes us capable in this area, and when you are done you can't go on building things for other people". It almost seems like a fatal attraction or overly obsessed/attached owner/girlfriend.
Non-competes are a kick in the nuts really to put it bluntly. You'll know the feeling when you get one. It is closer to a company trying to own a skilled worker rather than a partnership.