I think your point is not informative. The point of the video IS a real test comparison between what is an actual sapphire screen, and apple's sapphire. Since a lot of people think that the apple watch cannot be harmed by anything less than a sapphire's hardness (which isn't true), it's important to know what is actually being provided in terms of scratch resistance.
This could very well be the difference between getting a few scratches on your screen over time which is annoying, vs. not getting any. Having a sapphire screen is to almost say you have an "invincible screen", that cannot be damaged by anything short of diamond. As you can see in the video, apple's watch display is not that. This is also evident of the plenty of forums on here where people do get a scratch on their sapphire screen and are confused as to how it happened (meaning it was not a significant event that caused it, just daily use). So there are certainly cases dissimilar to yours, where the opposite occurred. My job is not to tell you apple sucks, it's to spread information. I did originally myself think sapphire display meant 100% sapphire display, however in apple's case it doesn't, it's basically one step down from it, in terms of being scratch resistant.
On a day to day basis you may find similar scratches come in the from of any outside material, concrete, brick, cement, anything in my apartment garage comes to mind. While not everyone knocks into things all the time, having an actual sapphire display would help with these; however you're not necessarily safe from a big ole scratch just like that shown in this video.