When I first got my yorkie and was trying to teach him to walk, I thought it was okay to drag him to teach him it was okay to be walked on a leash but found when I got home that his pads had been scratched by the tugging because they had bled all over the carpet. I felt awful and never tried to 'teach' him in this way again.
So, I guess members here are painfully aware of the issues we bring on our dogs when we attempt to walk them without the proper techniques and equipment. As such, they like to ensure that people who post videos like these on this site are aware and are not sending a message to others that potentially harmful acts done out of ignorance or cruelty are acceptable.
However, the puppy in this video seems well cared for and didn't appear to be in any distress so I do get the humor especially since the puppy also looked at you like, "Duh," when the harness slipped off.
We're all on the same team, I'm sure!