Jauron stays on because mediocrity is the perfect result for Wilson. Big success comes with big time salaries, big raises for coaches, and lots of unwanted attention and controversy that always comes with being in the spotlight. Losing 12 games or more means unwanted media attention to spend more money, lower ticket prices, and deal with bad PR, mass public outcry, and less revenue from merchandise sales.
Ralph would love nothing more than to have a smooth, quiet 7-9 every year for the rest of his life - whether we like it or not.