They like to base their game design on proven principles and have a hard time altering or expanding on those principles after they have discovered what works.
That's a tad unfair to Nintendo. While it's true that they'll usually take a more conservative approach with a lot of their projects, they've also experimented and taken quite a few risks over the years with their properties - certainly more than the likes of Ubisoft, Activision or EA. Whatever their process may be, they've released far more good games on a consistent basis than the aforementioned three, and actually launched completely new franchises too.
As for other Japanese developers, they go from one extreme to the next. You have developers like Yoko Taro or Goichi Suda that are certainly not afraid to experiment and try new stuff, to companies like SE with Dragon Quest or Game Freak that take an iterative approach to (certain of) their franchises, and then there's companies like Capcom that sit in the middle.
At the end of the day I still respect big Japanese companies like Capcom more than Western faggot factories like Ubisoft. Just compare Resident Evil and the wide variety in gameplay, art direction, storytelling and themes to AssCreed, or Call of Duty, or BioWare trash.
It's why a project like Elden Ring which apparently started out as quite ambitious is scaling down to DS3++.
Isn't that true for most developed games though? They start out with grand ideas and the more development proceeds the more they have to scale back. That being said, with From it's a tossup whether the game turns out to be great (Demon Souls, Dark Souls, Sekiro, Bloodborne - to just name the "Soulslikes") or somewhat mediocre (Dark Souls 2 and 3). I still think Elden Ring will turn out good, if only because it's been their main focus of development for so long, so it's not going to be undercooked like Dark Souls 2.
Well, people die from overwork in Japan so... Who knows?
They even have a word for it, karōshi - it's been something Japan has been struggling with for decades now, doubly so because even the government and companies realize that work under such conditions usually doesn't produce good results and ends requiring even more workhours to fix, but it's difficult to change behavior that is so engrained in people. The older generations actively seek out ways to avoid obligatory, government mandated vacation days, while many from the younger generations - especially those not planning to start a family - will rather seek part-time word that can cover their immediate needs and leisure than enter the salaryman wagie cage.
As with most of these claims, there's likely a glimmer of truth to them, but he's also comparing Konami, who have by and large exited the gaming market and now focus almost exclusively on the pachinko mines to a company still developing games. Also, the sad truth is that making games has always been an extremely demanding commitment - I remember reading about id's work practices back when they were making Wolfenstein and Doom as an example.