"Cater to my requirements"
The hell are you even on about?
"Muh-self insert design"
That's the joke. The series from the very beginning makes it a point that Saitama doesn't even enjoy being OP and wants an actual fight. And Genos is there from the beginning as well. His whole arc is just as much a part of the story as Saitama being OP.
Has it ever occurred to you that aside from Saitama and Genos, there were also the villains from the start? Those who, conveniently, are your typical annoying types that normal people are bothered about in their daily lives, and had always fantasized punching them in the face once or twice? How convenient it is, that the self-insert Saitama is always being there to fulfill that exact fantasy of normal people. Telling me I have to look more into Genos's fantasy world-saving story, and to have to wash away Saitama's mundane wish-fulfilling story is the exact kind of ironic moronic "cater to your requirements" I'm talking about. Again,
I'm reading the story,
I'll take away what
I needed from it. Go eat a bag of dicks if you think you can tell me how I must interpret the story.
"The gist of a story"
Yeah, and that's a giant load of BS. It's not the story or author's fault if you ignore everything else for just for the most surface level premise.
Just to give an actual example, there's Vinland Saga. People got mad at it for focusing more on introspection and pacifism in season 2 and called it a betrayal because "vikings and revenge plot" despite the fact that all of those themes were present since episode 1 and the series spent pretty much all of season 1 beating you over the head with it. That's not a betrayal, that's people not paying attention. Same with Attack on Titan and post basement reveal. Even if it weren't, the idea that a story should only stick to core surface level premise is stupid and does nothing but stifle stories.
To raise Vinland Saga and Attack on Titan to compare with One-Punch Man in terms of reader outlash is simply inadequate. Whereas the former two are obvious in their "adventure" genre - that they have a story to tell - the latter is equally vocal about its "action" genre - that all are basically set pieces for cool fights. Obviously the former will deploy their stories beyond their "surface level premise" and any remotely competent reader could discern that. Obviously the latter will ride on its powerscalling fantasies to continue to fulfill readers' ego and power-trip. So, if the stories themselves are unequal, then the outlashes - however similar they seem - are also unequal. In this case, the ones you mentioned are bs, but the one I mentioned have merits. OPM earned its audience through wish-fulfilling self-insertion, not through compelling storytelling, so in turning away from wish-fulfillment, it betrayed its oldest audience.
If you are still not convinced, simply ask yourself this: If the author had completely removed the Saitama aspect
from the start, would you have followed it? What would OPM then, be any different than Bleach, Naruto or the million other similar battle shounen series? Similar giant cast all with colorful designs, various powers and different personal journeys; similar bigger-than-life power systems and world-domination scale conflicts. What exactly then, would set OPM out from the rest? The answer: Nothing. And it would fall into obscurity just as fast as Genos.
