Why people take the soldier mindset?

 They take it becuase of: belonging and comfort.

Belonging: Suppose you belong to a church, but now you have lost faith. So, you think of leaving. But leaving also means abandoning your family, and friends. Would you be adamant? If you would, you took the soldier mindset.

Comfort: The soldier mindset gives you loads of it. Isn't it so much comfortable to avoid everything that denies to your ideology?

You accept it or not the soldier mindset is not a good option. It can put an innocent in jail or even to death. 'I am right, everything except my ideas are wrong.' it says.