Why did my Korean roommate report me for eating in the dorm room? > Issue

When I came to Korea as an exchange student, I was excited to meet new people. I was placed in a university dormitory and assigned a Korean roommate. Everything seemed okay at first.
But after a week, I got an official warning from the dorm office.
 Why?
 Because I was eating instant noodles in the room.
Apparently, my roommate reported me. He said it made the room "smell bad" and "disrupted his concentration".
 He never even talked to me about it directly. Just... reported me.
I was shocked. Back home, this would never happen. Isn’t it normal to eat in your own space?
 After that, he stopped speaking to me. I started eating outside, even in winter.
Now I’m wondering:
 Was I really wrong? Or is this just cultural difference?
Has anyone else experienced this?
 I really want to understand—because now I feel like a criminal just for having ramen.