USA was based on the principles of Locke & Paine, and we also kill on a large scale. Israel was based on the principles of Theodor Herzl, et. al., and they kill on a large scale. Maybe people just like mass murder when they think they can get away with it.

Have you read either of those books? The only reason anyone ever read Mein Kampf is that the party literally gave it away and people were expected to own a copy to demonstrate their loyalty. Few people read it at the time, even fewer were inspired by it. The Nazi regime was literally enabled by Christian conservatives hoping that imbuing Hitler with dictatorial powers would lead to the end of democracy and that he would cede his powers to the Kaiser once he's done eliminating the lefties. I'd go out on a limb and say that even of those in more recent years claiming to have read the book or be inspired by it, most are just name dropping it for dramatic effect and haven't read it cover to cover.

I'd imagine more people have actually read Das Kapital because unlike Hitler, Marx was actually providing useful insights. But if you're inspired by Das Kapital to do mass killings, you'd also be inspired by reading a stack of spreadsheets or IKEA manuals. It doesn't even clearly define capitalism as a problem that needs fixing, it's a useful analysis.

Mein Kampf was a guidebook outlining the steps needed to overthrow the German Republic. Das Kapital is a dense and boring treaty on Marx's theory of economics. Comparing the two shows how shallow your understanding is.

Also, do you believe that billionaires and workers have fundamentally different and opposing interests and incentives? Then you subscribe to the core of Marx's theory too.