Am I missing something or isn't it kinda off how the main cook and son of a restaurant own...

Am I missing something or isn't it kinda off how the main cook and son of a restaurant owner doesn't know what medium rare is? I'm genuinely asking cuz it seems like it's just there to emphasize the point of the chapter when the fact that jinhyeong's dad owns a residence there already did a good enough job at that imo