I'd rather not have new ideas for businesses filtered through "can afford zero income for N months".
There's nothing wrong with choosing to have a family and raising kids, but that is a choice. No matter what conditions are set, the person who makes the necessary tradeoffs is going to be in a better position to succeed and YC as a business entity can do nothing to level the field for people who are willing to go all-in versus people who prioritize a comfortable home life.
Again, startups are privilege that form out of the security of societal infrastructure and excess of wealth. Nowhere in society is it prescribed that everyone should be able to forego having a job and drain their savings to gamble at a chance at massive wealth. How is it reasonable that we've come to expect this as some sort of entitlement?
The top comment makes a dismissive remark about "rich white men," and YC being against inclusivity and diversity. The natural response to this is that YC is not racially exclusive, but that they exclude based on those who can assume risk. Yes, but white people are rich so they can consume risk and black people are poor, therefore YC is in reality discriminative against blacks. The simplification of this kind of argument and its decontextualization from reality should be self-evident. Unfortunately, it's emblematic of the kind of emotionally reflexive and broadly appealing arguments we see thrown around instead of practicing any form of intellectual sophistication or nuance. It's far easier to make a glib side-remark suggestive of racial privilege. It's even easier when this is politically and socially trendy, even expected, and the individual making the remarks is protected from backlash by the insulation of a particular ideology.
It's about number of people who can take risk of having zero income for N months. That is such a small group of people, and this narrows the pool of people who might found a startup that could change the world (or part of it). It means that all the ideas for startups are coming from people who have (at least) one thing in common. Maybe it's not the optimal thing to have in common?
ps. I did the startup thing with a wife and a daughter. These days you know it as Amazon.
YC is a business entity not a non-profit organization dedicated to wealth distribution. You're asking it to do a job outside its core responsibility (profit, survival). If you want to make the argument that YC should up it's funding, that argument has to establish itself as being strongly in the interest of YC, otherwise it doesn't make much sense.
YC isn't under an obligation to do the best it can for society. But if it wants to do that, or even to approximate it, the filter functions it uses implicitly and explicitly need to be considered carefully. YC has said a variety of things that indicate that it does have some desire to trend in this direction, at least in the past.