Though keep in mind that his palate is especially refined. Average Joe buying a coffee at Baskin Robbins isn't going to notice the difference between different high end grinders.
Besides, I've watched a good few Hoffman videos - including his high end grinder reviews - and while they are great, they aren't scientific standard double blind tests. They're just him in his kitchen.
I did search in case I missed anything, but can't find any videos that you might mean. If you have a specific video in mind, please link it.
Maybe look more into who he actually is before dismissing him? He's a National Barista Championship winner and has decades of professional coffee experience and knowledge beyond just brewing a daily cup. He also co-founded a roasting company that became the largest wholesale specialty coffee supplier in London. It's not like he just popped onto Youtube one day in 2016 and decided to start making coffee videos.
What I'm less convinced by is that more and more expensive grinders taste better to any noticeable and consistent degree. Personally I'd say that the taste changes day by day, maybe according to my mood, whether I brushed my teeth or ate something sweet in the last hour or two, the humidity, bean freshness, whether any defect beans got into a particular cup, and probably a ton of other factors.
I'm willing to accept that my tastes are not developed enough. But I need real double blind tests to back that up, not just people saying I should trust them because they claim to be an expert. Are there any?