re: I dont understand why these buyouts exist?

Right. If you find the truly in demand people in the private sector there are employers willing to throw all kinds of incentives at them in order to retain them, including rich severance agreements. Just look at the so called "golden parachutes" that are given to top level CEO's. You can negotiate those kind of benefits if the company employing you thinks that you are valuable enough. That just isn't going to be most people.