How come women are allowed to live at home with their parents past 20 but don't get called out?

It's very normal for young adults of both genders to still live in the parental home past early 20's.  Here in the UK you need 9.4 times your salary to be able to afford a home, unless you live in a part of the country that has cheap homes.

I think the question is kind of backwards. Since when is living with your parents something that needs to be "Allowed"? We should be asking ourselves why people feel the need to leave home at all.
It wasn't that long ago that humanity valued the big family that stayed together until death.
The degradation of the family unit is the single most destructive trend in the last 100 years of human evolution.
Remember the Walton's family TV Show? Many families use to live like that. Many still do in other countries where they understand the value of family.
Leaving home 100 years ago was only done to go to work or university. It wasn't uncommon for in-laws to live with your family either.
I believe the reason for so much hatred among people today is because we've forgotten how to live together in love and harmony as a family.
We don't develop loving nurturing relationships without family support and encouragement. It has become quite acceptable to have children out of wedlock, and the number of kids born into unstable single-parent households has risen to appalling heights. Thirty percent of white, 50 percent of Hispanic, and 75 percent of black children are now born into such families. Their chances of success in life, regardless of ethnic background, are tenfold less than peers lucky enough to be born in what used to be the gold standard: The two parent home.Many of these children, especially the boys, no longer learn civilized behavior at home. Ask any inner-city teacher why they have so much difficulty teaching, and they'll tell you over and over it's due to behavior problems in the classroom. Our society is doomed because of this, unless we somehow turn it around. Don't expect to be closing any prisons until it is once again uncool to have children without a dedicated man in the house.
Family traditions, farms, and love for God is all but gone now.
We suffer as humans for the loss of the family unit and the support and encouragement it once provided us.
I'm not going to get into what is responsible for the break up of the family unit, because its too in-depth for this forum. But only wanted to clarify the fact that many people are blind to the suffering it will cause many generations to come.
Together we are strong, separated we are weak and vulnerable in many ways.
This is a good question Frankie, I'm sorry you have to ask it.

You don't hear about it, but it can be just as unappealing. For me it depends on her exact age. If she's between 20 and 23, I can understand if she's still living with her parents because maybe she's not done with college or just graduated. But after 23, I'd begin to question why she hasn't become financially stable enough to live independently if she is in fact working. Hell, I bought a house at 25, but I never went to college or fell into student debt. Not that I expect her to also be a homeowner like me, but at least live in an apartment. If she isn't financially stable, I won't date her.

In some cultures, women are expected to live at home until they get married. If they don't marry, then they are expected to live at home all of their lives so they can take care of their parents and help raise their nieces and nephews.

You seem to be conflating your dating woes with the fact that almost no one right now is calling anyone out for taking refuge wherever they can find it. You may be in for a big surprise when these same women will still refuse to "date ya" even when you do "start making some real money". 

Men are seen as “unmanly” if they live at home?  Really?  Anyway I’m glad you’re fighting t he stereotype I guess.  If it’s actually true.