Magneto’s insistence that non-mutants are and maybe should be subservient

Magneto is a prime example of “might makes right”, which is why he’s a villain. Non-mutants are beneath him: he has no compassion for them, no regard for their ideas, their voice, their opinion.

I’m not well versed in his history in the comics or whether there even is a canonical backstory, but from the Marvel perspective ….. he’s a sympathetic villain, because he has a good point. While it’s not a single coherent backstory, we can see his development over time at the treatment he faced, and can have sympathy for humanity driving him to it.