Besides Karl Marx being generally held in high regard among people who are criticizing the mocking of those predatory practices, it's just an analogy.
It's like getting angry about mockery of the tobacco industry using feminism at some point to get women into smoking, because it puts feminism in a bad light and punches it down or whatever. Or China using feminism to pacify, if not outright genocide Uyghurs[0], for the same reasons.