First: I haven’t seen the film, and have not really paid any attention to it, but the negative reaction doesn’t surprise me one bit. I also doubt it’s going to have much impact on its success—it’s already closing in on 1 billion USD after just over two weeks, making it a contender for the most successful animated film in history.
I’d say the vast majority of people being hyperbolic and overly dramatic in their negativity are pessimists trying to sound important. By being negative toward tons of stuff, they’re trying to sound like they have superior taste because they’re sensitive to flaws. The vast majority of the time they’re nitpicking—making a mountain out of a molehill. But, there are a lot of pessimists on the Internet who seek out that kind of content and are impressed with people who have these negative views on everything (often with injected conspiracy theories, like “the woke mob is taking our Transformers!”. There are enough grift buyers that that these professional pessimists have become rich by basically shitting over other people’s or studio’s work, that is most often objectively great… in fact, it seems to be that the more objectively great something is the more shit it gets—The Shining, Avatar, and Titanic to name a few, each one a ground breaking film, shit all over in their times (note: Titanic and Avatar were both insanely successful financially and critically, but were basically Lucifer as far as Internet pessimists go).
I’m not talking about AVGN. Those videos are parody of nerds for entertainment. A lot of the games he bashes he gladly plays in livestream. The character seems partially inspired by himself (as a critic) and his friend and former producer, Mike Matei, who was known for his authentic game rage and angry opinions.
Bottom line, everything is much more entertaining when viewing from an optimistic lens. Now, that doesn’t mean people will enjoy everything. But for the most part, almost every TV show and film is of a fairly high quality and is fairly easy to enjoy for fans. It’s rare that something is genuinely bad and gets through the filters. In the end, it’s a matter of taste. For me, I’m not a big fan of the overused heroes journey film formula, or “three act structure” as it’s often branded now, but there are a few I like for other reasons (such as aesthetic).
As a note, a lot of the time films or books are described as “three acts” when it’s not the case. Three acts are basically: Act 1 inciting incident to threshold determining the main conflict; Act 2 is rising action; Act 3 is the all is lost moment, the climax, and resolution of the conflict. There’s such a faith in the idea of the universality of the three act structure that people force it onto describing stories that are (in reality) significantly more complex than that, or don’t even follow the structure. The reason why anime films are often more interesting than Western animated films is because their plots are more complex. Western animated films often do follow the three act structure to some degree. Anime, on the other hand, often doesn’t have an inciting incident, but rather start with the introduction of characters and implied or expressed motivations. While there’s often a hook, or some kind of event early on, it’s usually not a driving factor for the plot so much as a way to show the character in crisis. The equivalent to a threshold is often an inevitable event that was already scheduled to happen: Kiki is old enough to travel, and now she’s doing what all witches do, and traveling. Princess Mononoke is one of the rare films from Ghibli that has something like a proper inciting incident (Ashitaka gets cursed and now must leave), but that’s about where the similarities end; the story from then on out is about establishing paradigms and then subverting them with a twist—which is a lot of what anime plotting seems to do, although usually one big twist or chaos event, rather than the 3 or 4 that Princess Mononoke had. Apart from Hitchcock films back in the 1950s, mid-film twists are actually fairly rare in Western film, instead opting to have them at the end. Another difference with the three act structure is there’s usually an early “world” that is thrown into chaos and then it becomes a new world at the end of the film; this chaos moment often occurs toward the end of the anime film (Akira), or sometimes it occurs multiple times (Princess Mononoke, Spirited Away). But anyway, this side note has become excessively long and is off topic, so I’ll stop.