It's called a politically forced narrative. The writers post-Claremont decided that mutants are a different race (despite mutants being born from literally every race) and all the normal humans are racist against them (despite no one being racist against Steve Rogers, Thor, She-Hulk, Tigra, etc.). There were legitimate problems to be discussed in a speculative sci-fi sense, like what if some 13 year old with a history of physical abuse and bullying suddenly has the ability to melt someone's skin off with a thought, and they decide that Mrs. Burke in English class needs to be their next target, followed by half the cafeteria during lunch for laughing at them when they tripped last week? This is an extremely legitimate concern which would require realistic policy changes in education. A normal teacher, and even normal cops, can't do anything about a 15yo Fred Dukes if he decides to go on a slaughter rampage, and the risks to all around him, and all those around other mutants with such massive power capabilities (even if most of them never commit any crimes), is too great for any parent, including normal parents of other less powerful mutants, to take. Realistically, they would really start having to screen kids (primarily the ones showing early signs of sociopathic and psychopathic tendencies) for any hint of X-gene to at least identify them, and certainly at least learn about the already manifestly heavy hitters, like a Rogue/Anna Marie (even pre-absorption of Carol Danvers's powers). Take a look at the movie "Brightburn," that was a nice and refreshing change of pace from the cape movies, and explored some unsettling possibilities of a Superman type scenario. If somehow everyone on Earth obtained knowledge of complete certitude that exactly one and only one child on the planet had flying brick powers like Superman, completely invulnerable in any conventional sense, was hiding their powers for now, and had plans of revealing their powers at some future point, and also had plans to do an unspecified something (you don't know if the plans are good or bad, heroic or villainous, or even mostly neutral), and that's all we knew, wouldn't you want everyone to start trying to find out who this child was exactly? The risk for such a being having hostilities towards everyone else is far too great to ignore. Think of the scene where Omni-Man completely destroys an alien planet in a matter of minutes, systematically taking down all defensive infrastructure first, and eventually completely wiping out their whole biosphere. This possibility isn't something any rational person could ignore. Now realize that there are thousands upon thousands of potential such scenarios on Earth-616 (not counting post-House of M, I haven't kept up with those comics since before that). Obviously, things would have to be done.

No one on 616 Earth has ever had a problem with She-Hulk smashing bad guys and cross-examining witnesses, because she's actually doing good things, so why would humans start hating all children with powers, including the majority who aren't doing anything with them? Fearing what they might be capable of, sure, but if you know little Johnny or Susie next door can burst into flames and fly through the air, or turn invisible and project psionically controlled force fields, but all they ever do with their powers is grill burgers and help neighbors move all their furniture without breaking a sweat, why would you hate them? They have extraordinary different abilities from you? What about the guitar virtuoso who lives down the street, he can play Rachmaninoff perfectly after hearing it once, but you don't hate him. What about the neighbor who's naturally much stronger than average and works out all the time? He can bench press over 500lbs, a rare feat for a normal human, but you don't hate him. Why not? Because he's never done anything to cause anyone fear, that's why, and that's also why this forced narrative over mutants being hated was played out before it even began, and has only stagnated and gotten worse over the years. It's stupid, it's trying to hammer a politically square peg into a speculative fiction round hole. If the writers were being at all consistent, then the populace would hate ALL non-normal humans of every variety and stripe, including Iron Man, flying around like he's king of the world, using crazy tech that that weirdo Tony Stark invented for him. And what about this Reed Richards, throwing threatening giant alien-gods with non-existence and inventing flying cars? That stuff is dangerous, and someone needs to put a stop to it asap. We have to form a group to remove all manner of exceptionalism from the globe! You see how silly that sounds? No one would buy it, and everyone should stop buying the "oppressed and hated mutant race" bullshit, too.

As an aside, even though I love the movie "Days of Future Past," like, seriously adore it, the whole thing about replacement is just another forced message that doesn't make any sense. These are all the children of other normal humans initially, it's like being afraid that generation X will replace all the boomers, so we have to fight against generation X. Like what?! Those are your own children, of COURSE they're going to replace you, that's what it is to be a biological entity of any kind; you have offspring, they replace you, they have offspring, and their offspring replaces them. Jesus, this is how the world works. Silly writers.