You can see their role as messengers of the truth pretty often. I saw this one video that I thought was pretty great where a group of three women were out. The videographer/interviewer had the two friends call up the first's boyfriend and ask to "hang out" behind her back as a sort of joke. The first woman then freaked out, not at her boyfriend for wanting to cheat but at her friends for showing it. If you watch carefully this sort of thing happens pretty often.
This is a phenomenon in most of young generation US and EU too. Both housing and the ability to get on with someone are far cheaper and easier in Tokyo in particular, than most metropolises in the developed world. If that doesn't tell you there's more going on than "just your own place bro", I don't know what will. If women are continuously taught and telling each other that a guy must have their own place or they are bad / deadbeat, the entire thing becomes a self-fulfilling prophecy. Given our species as a whole has been procreating with less for most of our existence, I'm more eager to place my bets it's a cultural phenomenon rather than "biologically hardwired".
>You can see their role as messengers of the truth pretty often.
You can just as well say men are "messengers of truth" because they don't want to marry single moms. The only thing you're showing is that their words mean jack compared to their actions, as is the case with every human being under the sun.
Yup. It flips when everyone gets older.
>The awful part of all this is that young people blame women.
I don't want to blame women in particular, but from personal anecdotes, women in particular place huge importance on a guy having his own car and place, despite both being massive wastes of money here and actively hurting one's ability to get housing later. The opposite, not so much. This in a country where even rent is now mostly a dual-income market.