I think it's because a lot of women genuinely don't realise or believe that there are men who are not like that and so assume that every woman is with this sort of man but just not talking or being honest about it.
That’s the sort of things my very sexist dad would say
The problem is that there are some women who perpetuate this line of thinking.
For example. When I moved out at 18, I didn't know how to use the washing machine. I'd never been allowed to and I'd never been shown. The laundry was my mother's domain and I was told I'd "only get it wrong".
My dad and she divorced, and she declared she'd 'never wash another man's dirty pants and socks again". Only, neither her second husband (who lived alone and was quite capable) nor her subsequent live in partner was permitted to do their own washing or cook for themselves.
She'd chide them with talk of silly men and how they couldn't he trusted, they had no idea how to use domestic appliances and couldn't to do it right on account of being men. She'd pick fault in the domestic chores they did do, criticise their perfectly adequate cooking and tell them off (like they were children) for not doing things 'properly'. Some of it she told me about and some of it I witnessed myself.
And there was always an air of, "Look at him! He's hopeless! Where/what would he be without me?!" about it all. When they weren't hopeless at all.
She didn't doubt their competencies when it came to changing the oil in her car or checking her tyre pressure (because, of course, she was a woman and women don't know how to do that sort of thing). Only when it came to domestic appliances.
My ex husband, my current partner and my previous exes have all don't things differently to me. Not badly or incorrectly, just differently. I don't assume a domestic superiority because I'm female but some women do.