Privacy is dead and it started in the cradle.
The thing is the parents normalizing this kind of intrusion of privacy think they are in the right while creating a very dangerous world. Even things like going through your kids rooms (yes even when they live at home) is a huge privacy violation.
No wonder the "but think of the kids" argument is so effective, we all grew up being propagandized by or own parents and environment.
Privacy feels like such an innate desire. Your mention of parents going through your room brought back a few negative emotions tied to a few memories, where my mom either came to me with something she found in my room, or walked into my room and went directly to where something was hidden and pulled it out (indicating that she had already been snooping in my room and found it). Thinking about it, I realized that's one of the reasons I started hiding things where my parents couldn't easily get to them, like in the rafters in the garage, or in various forts and hideouts I created in the neighborhood.