Funny, it also displays "I'm not a woman" results in the first few pages.
As expected, it's mostly threads talking about women, sexism, etc.
The question was "Somehow though in my head all HN users appear as men...Is there any way to falsify?"
The results list multiple "I'm a woman in tech and <blah> <blah>", thus falsifying OP's assumption. What they were talking about is irrelevant to OP's question.