Without going this far as to say everything Square is publishing is garbage, yes i have trouble believing that games such as Diofield or Valkyrie are actually "great" and "awesome" and that i would have known better if i had played them.
I don't know if it's a thing with japanese publishers or if you're not even allowed to say Ubisoft games are shit without being called out for not playing them and not being an "enthusiast" (or perhaps this is because there are not AAA i don't know).
(i played games like Octopath though, nice game but i would not say great for example)
I don't think it's just a "japanese publisher" thing, it's just that a lot of people (myself included) really enjoy the types of games that SE has released this year. I'd rather play a variety of budget / AA games that try new and different things with mostly non-established franchises or new IPs than a single AAA mega-hit.
The difference with something like Ubisoft is that their games are almost always the same. Anymore, they're a lot like the annual sports games that get released every year, sell millions of copies, but are mostly identical to the previous year's sports game with a few updated stats or minor gameplay tweaks. It's easy to voice an opinion about the newest Assassin's Creed game - even if you haven't played it - because it's almost cookie cutter identical to the last 4 games in the franchise. The same is true with Far Cry.
Meanwhile, something like Diofield Chroncile is pretty unique (a real time strategy version of Final Fantasy Tactic's formula), so in this case you're going to get some pushback saying it sucks (when you haven't played it). You'd be forgiven for thinking it's just like Octopath Traveller, Triangle Strategy, or Various Daylife (they all use the same logo, so...) but it's actually a unique experience that a lot of people are going to feel like you need to play to judge.
Another example is the Voice of Cards games. They're pretty similar to traditional tabletop roleplaying games of yesteryear, and rely heavily on the game's narration being engaging (hence "VOICE" of cards). I'll be the first to admit that it's not for everyone, and I personally thought it was somewhat mediocre especially for the price, but I still think those games are awesome because they're engaging and unique and have qualities that are difficult to explain to someone who hasn't also experienced it.