I feel like the point is going over your head.

It doesn't matter that there is nothing on your computer. The point is that someone you trusted violated the principle of privacy, and went snooping without permission. It's the difference between someone overhearing something you said, and purposefully lurking outside the room knowing you don't know they're there, listening and purposefully hiding their presence.

The intent is implied by the whole "they swear they'd never do it again" part where you have to choose to believe them or not. You can't promise not to do something you can't control.

Again, it's not about whether you are hiding anything or not. It's about the fact that they secretly, knowing they did not have permission and choosing not to ask for it, went looking.

Have you really never had anyone take something from you without asking, and felt upset by it? It doesn't matter if you'd have given it to them or not, you feel upset that they didn't ask.