I've seen this guy. He's just trying to get his round in quick when it's super busy I think - can't blame him for wanting to play through. When it happens it feels a bit abrasive but I totally respect his determination to run through the course in like 30 minutes despite the large groups.
First time I was confused and a bit upset but when I thought about it I realized it made sense.
Also when I play alone and no one else is on the course I'll sometimes run after a throw I toss into the woods in order to have a better chance to find it. I also sometimes like to run on the first couple holes to get my blood moving when it's cold. I'm sure someone has seen me and laughed or been confused before though haha.