Where Nova got her technology is irrelevant, she could have gotten it from some other source - human or otherwise. Her technology may have symbolism but ultimately it wasn't the humans who are responsible for that act so it's a waste of time to pretend like it was.
Everyone knows how the X-men got here, that didn't excuse their methods otherwise it comes as excuses for their own decisions who sound more like they're coming from super-villains than super-heroes.
The Extinction Team is contractionary, it was made to be the Avengers equivalent for PR and an intimidation tactic. Cyclops lost a step from his Astonishing days with Whedon with public relations with this. It's a mixed message. And they folded like a deck chair when they met Sinister of all people.
This was the storyline where Emma First and the X-men teamed up with Norman Osborn. Which turned out exactly as you'd expect since he's Osborn.
Frankly, Genosha is a poor explanation since the only reason it failed from Nova's attack is because the entire country had no defences, which makes no sense given Magneto was its leader. They didn't have any military or airport radars to warn them? No navy or air force? No armies filled with powerful mutant super soldiers? Nothing?
Because the PF were so wrong in that. It's ok to admit when the X-men become the bad guys when they become the bad guys.
The Inhumans were clearly in the wrong there but their motives aren't that distinct from Krakoa. They, too, are a nation of super-humans trying to thrive and Black Bold unleashed the Terrigen Mist to destroy Thanos, any argument krkaoa has could be mirrored by them, what if the situations are reversed - if Krakoa unleashed a cloud on Earth that would revitalise their species and sacrifice others do it I really can't see Krakoa not thinking about doing it. It's not like the Krakoa cares about other species at the moment.
It's fascinating how Xavier looked at Attilan and went "I want some of that." They're following thee exact same path, including with second class citizens and the isolationism.
Humans have shown that they care for mutants in Marvel, including in the X-line, but the narrative that all humanity wants to destroy them would lose its urgency if that was acknowledged. With how mutants are spoken about you'd think they were the Morlocks rather than a First World nation. The only people who want to kill mutants are the bigots, who are presented as the worst of humanity - which they are. I don't think we should judge mutant kind by super-villains like Apocalypse, Magneto, Selene or Sabretooth, do you?
The Skrulls are a dying species, was it right for them to do the Secret Invasion because of this? They may have a religious angle but it's the same argument.