Precisely. And even without knowing that fact concretely, one ought to be able to easily deduce it; who were the most successful Capitalists of Marx's time? Invariably, Jewish Capitalists. Financiers, particularly.
One of the most crucial parts of debate is thinking about the issue from the other guy's point of view as well as from your own. That's something a lot of people here refuse to do -- if they're even capable of doing it at all. Understanding somebody isn't "dangerous"; it does not mean agreeing with them. It means having a well-rounded perception of the issue under discussion.