I think people asked because it makes a difference in the recovery time and how it's treated. A lot of people mistakenly call gastrointestinal viruses "the flu" and they are not. Recovery time for most gastrointestinal viruses is a few days at most. They usually don't result in secondary infections.
True influenza has high fever, body aches, and respiratory symptoms. My first symptom as tightness in my chest and coughing. The body aches and fever didn't start until several hours later. Secondary infections are not unusual and can be serious. Recovery takes longer. For me, I was barely able to get out of bed for 3 days and didn't really start to feel normal for a week. It really wasn't until almost 2 weeks past when I came down with it that my energy level was back to normal.