Originally posted by Arachnid1
It's mostly implied. Spoiler:
You hear about the Westchester Incident on the radio and Xavier is haunted by something he did in the past so it's safe to assume the Westchester Incident was caused by him. After doing some research just now though, it turns out the number affected in the incident was 600 which means he didn't wipe out all mutants. Just everyone at his school and some of the surrounding area.Also with Xaviers case, the seizures were due to a degenerative brain disorder like you said, but the actual power he wielded while lucid was pretty weak. He struggled to even control those horses and bring them back, whereas X2 Xavier could have done that on a simple whim. Same with Wolverines healing factor. It was a shell of what it once was. We can assume neither are really due to old age since the future in DoFP was just a few years before Logan and both Logan and Xavier were at full power.
We also know that Strykers son, Rice, owned the cornsyrup manufacture plant and that he's credited with having wiped out all mutants. He genetically altered his product to attack the x-gene and this supressed the gene in the entire population. I can't remember if this part is implied or outright stated, but it seems to be generally accepted. We can then assume that all the mutants that were still surviving lost their powers over time similarly, with Logan having the most resistance to the corn syrup thanks to his abilities, and Charles presumably just being so powerful that the effect probably took longer on him.
I got you on the Westchester incident, that makes sense
Spoiler:
still not so sure on the corn-syrup making active mutants weaker, more so than stopping more from ever being born, which was what Rice said and then Logan commented that no new mutants had been born in 25 years, iirc.Kind of feel that their DoFP selves was just an oversight by the writer/director, which is not uncommon in this franchise.
I think Cyborg-Soldiers were the ones who took out many of the mutants though with Caliban's help, he tracked them down; they did the killing, that also seemed to be the source of the mutant DNA they used to create the children
You could be correct though, do wonder if there's an official statement. Would like to know.