To start with, he thinks katana is roughly as good as a European longsword.
Yes, he said that on his video about katanas and longswords. Basically claiming shit like that it is a matter of preference which sword you'd pick and so.
He's also bought into the whole bullshido myth. There was no real bushido. The correct term is bullshido and that was manufactured by 20th century Imperial Japan as their equivalent of Nazi's Aryan people myth to be used by propaganda machine to turn the peasant farmers into a ruthless war machine.
But hey, it's the modern internet. If your answer sounds cool you'll get a lot of upvotes - even if you are factually wrong - and the ones that have the most upvotes are promoted over the more factually correct answers and get even more upvotes. Go check Quora some day. The completely and utterly wrong bullshit answers can have 5k upvotes whereas the correct answer might have 100 upvotes. But the avatar of the guy answering is a fox from Zootopia and he makes a couple of snarky comments and his claims are outrageously cool.
This kind of shit always gets the most upvotes. And people look at the upvote count and think "oh, it must be correct then".