He is a pretty well-known chef who was trained up the traditional way in Japan, and tends to be lauded for his knife skills (though not with the deba specifically), so I think he's probably doing alright at least. You're free to disagree of course, but the man's abilities as a sushi chef are pretty well established by sources other than myself. As an anecdote though, I have actually met him, and what you see in the videos is certainly not all he's capable of. That really wasn't why I used it though. Honestly, it was just the first video that came to mind of a person handling a deba where the knife was extremely visible.