Of course Xavier's dream was killed off by humans.
The ones currently running Marvel comics.
So the real question is, what went wrong? Was it the events of Deadly Genesis that made the X-Men not believe in Xavier's dream anymore. There were many sins Xavier's had to attone for, but I think it was at that point where he lost the respect of his fellow mutant family.
Iceman's Greatest Accomplishments:
I remember the What If comic book, where Legion manages kill to Magneto, and without him what caused the anti-mutant sentiment, the mutants are famous celebrities, loved by everyone, or where Professor X becomes the Juggernaut and without his presence, all mutants join to Magneto, or where Magneto and Professor X had formed the X-Men Together, the government is allies of the mutants, as Magneto has never been part of the villains.
This shows that the main problem has always been Magneto, he incited hatred against mutants
also the metahumans can be mutants in the DC comics, both have a special gene, the x-gene and the meta-gene, but in DC universe they are not hated, as demonstrated in JLA vs Avengers, in the case of Flash in the Marvel Universe and the Avengers in the DC Universe
For me this has always been a note of contention regarding "The Dream"....Yes, they are.
How in bloody hell do they expect humans to accept them when all they do is wreak havoc and loss of life fighting among themselves? Mutants have proven to be their very own worst enemy.
Sun and Moon
It's kinda gone in cycles, sometimes it's better sometimes it's worse.
Looking at it from a real-world publishing history viewpoint, then Magneto's attack on the missile base in X-men # 1 was humanity's first exposure to mutant kind, and therefore one can make a compelling argument that Magneto triggered anti-mutant sentiment.
But taking into account the history of the Marvel Universe, and the X-verse in particular, that has since been retroactively built, it would appear that the knowledge of the existence of mutants, and anti-mutant hysteria, predated the emergence of either Magneto or the X-men.
The question of who threw the first punch would be quiet a complex one to unravel...it often is in most real-world conflicts and once you factor the endless retcons and re imaginings of comic book continuities, it only gets worse.
The general consensus now, in the mainstream continuity and in most adaptations, is that once isolated incidences of mutants manifesting their abilities and causing damage began piling up, the existence of mutants became known and anti-mutant hysteria began. THEN Magneto showed up and things only got worse...