Why people turn their faces away when I enter my password?
Am I doing something wrong?


  
Because it is a courteous thing to do, indeed.

In other word, they are saying that you do the same thing when they enter their passwords. Unix by nature is a network-based, and a multi-user operating system. It is each user's sole responsibility to manage one's own password that nobody can crack (supposedly), and furthermore to ensure the security of the system in a collective sense.

However, it is possible for someone to peek on your password key strokes over your shoulder, either unintentionally or intentionally. In such case, you should tell someone, "say, no pun intended, but I do not feel comfortable you watching over my password key stokes. Please give me a moment to finish my login alone." This is nothing wrong or an impolite thing to say.

Please let other people know about this important security element in case that they do not know it yet.