Snorting out a laugh, he couldn't believe how naïve Wanda was. As a journalist, he had personally seen a darker side of government - it wasn't a stretch for StJohn to believe that they would try to eliminate mutants. Genocide.
StJohn didn't necessarily disagree with Magneto's tactics... he simply disagreed with Magento himself, the way he treated those who helped in their mission against the humans. Wanda and Pietro were prime examples - if Magneto's own children didn't escape his wrath, what chance did somebody like him stand? The answer: none at all.
"Who do I have to shag for another drinkie?" He smirked at Wanda and gave her a wink.