Non-mutant superhumans are perfectly able to pass on their powers to their children. Mutants are perfectly able to reproduce with humans, powered or not. Their is no intelligent reason whatsoever to consider them a separate species.
Right, just as there is no scientific or logicly sound Real Life reason for racism/Homophobia/etc. That's sort of the point of X-Men comics.
Imagine if Real Life neo-nazis declared that people who had blue eyes due to a mutation in the EYCL 2 gene were members of the master race, but those whose blue eyes were the result of a change at EYCL 3 were mud-people just like the rest of the brown-eyed masses. That is exactly how much sense the House of M (and Marvel comics in general) makes in regard to mutants vs. non-mutant supers.
Mutants tend to have much more varied set of powers, plus a greater chance of developing powers that are considered especially dangerous or invasive, like telepathy or reality warping. They are a much more random factor too, being simply born with said powers, whereas even if Spider-Girl is she can at least trace her lineage back to her fathers lab accident, something rarer and thus smewhat more manageable. The prejudice arises partly from the sense that mutants are somehow supposed to "replace" humanity in a cliched` Darwinist sense, something that many mutants believe. The place of normal superhumans in the Marvel world is actually mostly ambiguous; in House of M Spiderman would probably be thought of as having "cheated" to get his gifts (not to mention he posed as a mutant), on the other hand Doctor Doom explicitly did and yet manages to still be one of the most powerful mutants in the world. Not to mention most of the extremist anti-Mutant groups aren't exactly on friendly terms with normal superhumans either, plus the majority of normal superhumans are supervillains and so aren't really trusted anyway (for that matter, neither is Spiderman or a few other heroes.
Mutants keep getting used as a metaphor for real-life minorities (even though nowadays they could just skip the middleman) no matter how little sense it makes. X-Men comics are more about symbolism then realism this way. Realistically, mutants with dangerous powers would be feared the same way people with weapons are feared and mutants with visible mutations would be treated the same way people with physical deformities are treated. Since two ordinary humans can give birth to a mutant, there are no reason whatsover to consider them a different species.
While it's a safe bet that someone with tentacles growing from their face is a mutant, plenty of mutants look like ordinary humans. Discriminating by appearances makes no sense at all.
Going from 5,000 mutants circa WW2 to 3,000,000,000 in 2005 requires that almost all of the younger generations be mutants, and that even more of them have human parents or grandparents than in the standard 616 timeline. So why didn't they explore the implications of that generational difference?
In the House of M: Avengers spin-off, it is revealed that as Magneto rose in power, a lot of humans wished to become mutants. Magneto sent transformers around who were able to unlock the mutant potential of people where it was still latent. That contributed to the explosion of mutant numbers.
Which doesn't answer the question at all.
It means that people who are only passively mutants don't count in the 616 numbers. In House of M continuity, they became active mutants through technology germane to that universe, hence the rapid increase in numbers. There's also a chance people considered 'supers' or 'mutates' in 616 managed to 'pass' as mutants to receive the social perks; or people considered mutants in 616 are passing as non-mutants to avoid the social stigma.
Long story short, the infamous editor who shan't be named isn't exactly big on these ideas of giving fans what they want. Thus no character development for poor Spidey, and no development for the poor mutants either.
If the House of M represents Magneto's ultimate fantasy - admixed with those of Quicksilver and the Scarlet Witch - then why is it that none of these three wishes to resurrect Magneto's first wife Magda (mother of the twins), or his other daughter, Anya? At the end of the story, Wanda tells Magneto that he's still a horrible man, even in this reality - but would he have been with Magda and Anya restored to him? Their deaths were a big part (sure, far from the only part, but still...) of what pushed him over the edge.
As much death as Magneto's seen in his life, he's probably the type of person who believes in letting the dead stay dead. Sure, Death Is Cheap in the marvel universe and mutant heaven has revolving doors, but this is a guy who witnessed and survived the Holocaust. The number of people who die and come back (Thanos stories not withstanding) is likely a drop in the bucket compared to the number of people he's seen stay dead. So, he focuses his desires on other things; a mutant dominated world is a goal he can work towards and conceivably achieve one day. Bringing the dead back to life is the unproductive obsession of a man stuck in the past, so Magneto doesn't waste his wishes on it, however much he would like to have his wife and daughter back.
It's not his fantasy- its Wanda's version of his fantasy. She gave him the world she thought he wanted, and aside from the fact she wasn't thinking very clearly or deeply about it, it also reflects her not-very-high opinion of her dad- she thinks he cares more about mutant supremacy and ruling the world than he does his own family, and he wouldn't have started on that path had her mother and sister not met the fate they did. Magneto himself might have brought both of them back and might even have went further and prevented the Holocaust and caused a bunch of other changes, but Wanda doesn't know or believe that. She thinks her dad loves her, but she also thinks that he would always put his family second and his cause first. So she gave him the first, to bring about the second.
Is the series set in the 70's or in the 2000's?
Why did people hate Magneto's rule?
Because he was oppressive towards non-mutants, or mutants who politically or ideologically opposed him.
No, I think the original questioner meant "If this was the world as Wanda thinks Magneto always wanted it to be, why does it harbor any dissent at all? Shouldn't everybody be happy with their lot in life, whether lordly mutant or lowly Muggle?" And the only answer I can think of is that Wanda recognizes her dad has a deep-seated need for enemies to lord it over and unruly subjects to dominate by force. So the new universe contains stuff for Magneto to do.
Why did Xavier say that Wanda couldn't have kids? The only 'person' she's ever been with in a serious relationship is the Vision and he's an android which means he doesn't have regular genitalia.
It's worth noting that the Vision was not originally an android, but a fully functioning synthetic human just like his predecessor/alternate self, the Golden Age Human Torch; that's why the older stories use the Insistent Terminology "synthezoid."
Where was Jean Grey during all of this?
She made a cameo appearance as a school teacher.
How does House of M: Spider-Man fit into the rest of the plot? After the 1st issue it seems to go straight into 'What if the world never was reverted back' type of story.