I imagine it is a face saving measure. If the executive is being let go, it is easier than airing out his/her dirty laundry and risking a possible lawsuit. Or in the current case of our Spirit executives it makes the company look better than the unvarnished truth: Bob originally planned to stay a few more years and make bank with his stock options, but since those are in the toilet he is cutting bait and moving on. Don't panic, everything is alright!