Money Why would you work for Insurance, Defense, military, Amazon, killing kittens R Us.

Money.

Defense and Military you can want to work there for such nebulous ideas such as serving your nation, protecting your loved ones, security, etc. This would require you to actually believe in said abstract concepts like nationalism, community, family, culture, or truth, so that you actually want to defend your homeland though. This is easier to believe for me than the innumerable start ups that were making the world a better place via ad placement click through rates.