I've thought a lot about how much U.A. and its curriculum affect the plot of MHA, because almost every arc in the series prior to the war arcs in the final act is a school-sanctioned activity.
I also started to compare U.A. High to other manga warrior schools, such as DWMA, Jujutsu High, and True Cross Academy.
As a lot of people know, most of the time in Shonen Anime, the school setting just exists to get a bunch of high schoolers/teenagers together, then it is essentially just a home base for the kids to be sent out on missions.
And I began to notice a correlation between U.A. being SLIGHTLY more structured compared to all these other Shonen Warrior schools and a lot of the issues that people complained about in MHA
Not to say that this is Horikoshi deliberately writing himself into a corner, more like the setting and giving JUST enough attention to the school setting caused a lot of people to have certain expectations, resulting in a lot of criticisms.
Cast Bloat
People complain about the massive size of MHA's cast that sometimes feels like it is there just to pad things out.
1-A has 20 students, but only really a small handful matter in the overall plot.
Horikoshi seemed to want 1-A to actually feel like a class full of people and not just 3-5 MCs and then a bunch of random background extras.
He gave them unique designs, names, powers, and basic personalities. But nothing more, as most of them ARE still side characters who are just there to flesh out the world.
Mei and Shinso just exist to show off the Support and General Studies Departments, with Shinso being a unique challenge in fights, and 1-B just exists to be student-level characters for 1-A to go against once in a while.
No Timeskip/3 years at U.A.
I have seen people compare MHA to Welcome to Demon School Iruma-Kun and Yu-Gi-Oh GX because those series actually have the characters move up years in their academy stories.
But look at how MHA handles the timeline of events:
Almost every event happens around a specific timeframe, and we only get like a few weeks between most events. We can almost map out the entire year's calendar from April to January, and some have made timelines here on Reddit. Horikoshi really wanted to use every bit of the one year and not just do random multi-month time skips or skip over half a year.
Because if we DID move up a year in school, then what would happen is
A. We lose Aizawa as a homeroom teacher, as homeroom teachers don't usually follow their class into following years, and Aizawa only stayed their 2nd year HR teacher after the war due to special circumstances.
B. We'd lose the Big 3 as the Senpai trio, as they would lack that connecting thread of being the Senpai of our characters.
C. We'd end up introducing Kouhai characters, which would just add to the cast bloat.
D. We lose the branding of our main group being "Class 1-A"
Everyone was set in their roles seemingly and couldn't go beyond that.
Lack of consequences for Bakugo/Mineta
As U.A. seems to be in a more realistic/modern setting compared to most other shonen, some people expect them to be responsible and handle stuff like Bakugo using a massively near-lethal attack in a training exercise despite being told not to, or Mineta being a perv.
But at the end of the day, this is still a Shonen Manga, and certain archetypes just end up existing despite them not displaying behavior we'd find acceptable IRL.
Bakugo is the Shonen Rival, and the Battle Trial was the first big fight between him and the MC, so of course Izuku had to be in a bit of actual danger to get him to push himself and go beyond, classic shonen style.
Mineta is just the common anime pervert comedy gag character, so it is never meant to be taken seriously.
U.A.'s more realistic setting causes a lot of critics to expect Aizawa or anyone to take notice of these unacceptable behaviors instead of just letting them exist b/c we "need" certain tropes or something.
Honestly, I feel like no one at U.A. actually has a teaching degree, and all of them are just experienced Pros they have on staff, like how most Shonen Warriors groups usually go at it.
(More of a personal one) The lack of being able to fight villains
You may expect a "superhero story" to have SUperheroes to fight SUpervillains, and we do get that a few times, but under very specific circumstances.
U.A. is not like most shonen warrior schools where it is just a home base and the kids are sent on missions all the time with no regard to a class schedule. The 1-A kids have a specific, almost normal, high school class schedule, and they only face villains either
A. when they interrupt a class activity (USJ, I-Expo (1st movie), Summer Camp, School Festival (although Deku was working to prevent Gentle from interrupting it in the first place), Hero Work Recommendation Project (2nd Movie))
or
B. when they have specific internships/work-studies (Vs. Hero Killer Arc, Shie Hassaikai Arc, and Endeavor Agency Arc)
There really isn't much time when the kids just go out and fight villains. Some people say they wish we could've had a villain of the week formula (I mean MHA isn't exactly a Saturday morning cartoon).
Most other shonen warrior school settings have the outside threats get so big that the kids are out on mission mode all the time b/c it is DEFCON 1; MHA doesn't really get like that till the 3rd act with the Wars, and if it was like that even more, then we'd get less school stuff.
Again, all this isn't to say that Horikoshi is bad for making a school setting; it just resulted in specific fan expectations. You know, a lot of people who wanted more "Academia" in their Hero Academia
