My 2cents - Avis employé Senior Manager Lockheed Martin

Jobs are principally tied to government projects, which are not predictable at times and tied to the whims of government decision makers and politicians, e.g. for a couple of years you are asked to sacrifice your work-life balance for the country to delivery urgently needed capability, you are accomplishing the impossible, and then your program is cancelled without cause because a new government official wants something else.