The only reason "lunatic" feminists seem more visible is because people feel compelled to point out the most extreme views of "lunatic" feminists every single time there is a discussion of feminism.

It would be like if every time a science article was posted on HN you had multiple people pointing out that all science is crazy because some lunatics used to think eugenics was a good idea.

Seriously, pick any thread on HN vaguely related to feminism and you will find multiple people claiming that feminism is a worthless lunatic ideology not based on reality. And 99% of them use outdated theory (just as eugenics is outdated) and complete misrepresentations to back up their claims. For example saying things like:

"oh, wait, one of the leading feminists (Alice Schwarzer) is strongly opposing any legalisation of prostitution"

When in fact her position is nowhere close to that:

"She views prostitution as violence against women and favors laws like those in Sweden, where the sale of sexual services is legal but their purchase is not. (See also: Prostitution in Germany.)"

It's pretty ridiculous to claim that feminism seems crazy because fringe feminists are simply more public, when you are directly and purposefully contributing to making them more public in a pretty transparent attempt to discredit feminism.