They expect to own you until the day you die.

Interviewed for a job there. They asked how long I would want to work for them. Told them I'd absolutely love to work for them as long as they can host my visa, and I'd love to even become a citizen.

That... Was not the right answer.

The interview was over from them on.

I still do not know what I said wrong. They don't allow remote work so... Do they want me to become an illegal just to work for them?

They can but it's unusual. They have an honor system and expect people to quit. They'll go as far as sticking people in a room with nothing to do and not able to sleep until they give up, essentially adult time out.

I don't know the full story, but that is apparently somewhat true. That's why you'll hear in games and manga that someone in a fairly auspicious position will get punished by cleaning toilets or something.