Security is about understanding reasonable threat models. 99.99% of reasonable threats to your machine involve theft or loss of the entire machine and personal data or accounts being accessed. This doesn’t require advanced attacks or paranoia nor does it require extreme measures to protect against. No installer will create such a configuration without a passphrase because its a simple and effective step to take to protect your data that is enforced by systems created by people who are all smarter than you.
Your cute statement about child porn is tasteless and thoughtless. I don’t take reasonable precautions like taking 5 seconds to type a password because I’m paranoid or criminal I do so because I have basic common sense.
“Arguing that you don’t care about the right to privacy because you have nothing to hide is no different than saying you don’t care about free speech because you have nothing to say.” en.wikipedia.org/wiki/Nothing_to_hide_argument