This point is not right, especially in the developing countries like India, China etc. You simply have to marry to stand a chance!

And, so, do you blame the man? As feminists have?
Or do you blame nature for being harsh and unforgiving?

By splitting the roles, mankind is much stronger as a whole.
Now, a woman can be much more focussed on caring.
She doesn't need to be strong, to support all that extra muscle mass. She doesn't need to be able to turn off or compartmentalize her emotions (important for hunting and killing animals)

For further research, i think the book is called "The Marriage Strike".
If men were actually in charge, would modern marriage laws and child support laws be so onerous?
Marriage, for a man, is not a net negative, it is only a negative.
He gets nothing, legally speaking. He can even be accused of rape, although the base tenant of marriage is that she is selling him her reproductive capability.

Even further, marriage is the only modern practice where men can go to jail without trial.
He is responsible for all the children she has, whether they are his or not. (and ¼ are not, just based on blood analysis) And if he can't pay the child support, it is off to jail, without a trial.