I'm a man and maternity leave does not bother me despite it being "discrimination" on the face of it. For one, maternity leave isn't really equivalent to vacation. Taking care of a newborn baby is very hard, exhausting work. To add to that, giving birth is a pretty physically traumatic situation that a woman does have to spend time recovering from.
Ultimately, no two people at a company are going to have identical benefits. We should try to be fair and equitable, but that means different things to different people, and is not always clear-cut. I can either wring my hands that someone somewhere may be getting a better deal than me, or I can actually go ahead and try to improve my situation. I don't see any point in trying to knock down women who want to be mothers because they may be getting a benefit that I'm not.
And finally, there are strong arguments for mandatory maternal (and paternal) leave from a societal perspective. I'm not going to rehash them here, but they're there if you really want to understand the other side.
It's not a reward a company bestows upon an employee for having a child, nor is it a mechanism for discrimination towards those who don't have or choose not to have children.
It's a way for an employer to support an employee in an important life choice, and is one of many benefits that a company may provide to foster a nurturing and open office culture.
FWIW, most states don't even require employers to pay for maternity leave and are only bound by FMLA. Newly-minted parents usually take accrued PTO, sick days, and declare disability to take care of their newborns.
[EDIT] For context, the parent poster (whose comment is now deleted) wrote about feeling discriminated against when a company gives maternity leave to parents but got no vacation time for choosing not to have kids. As an aside, I am confused by why the poster felt discriminated against.
There are hundreds of millions of people who would very much like to come to the United States. They are ready and willing to start working and contributing taxes now. We can pick and chose the skills we need, not invest for 22+ years and hope for the best.
We only need the product you are selling because you use your political power to prevent your competitors, with a superior product, from entering the market.
That's predatory behavior, not altruism.
Westerners in general isn't child-hostile, even if US labor practices are, and many of those immigrants -- including the Hispanic ones -- are Westerners themselves.
What we have going here is attractive enough that we have people lining up out the door. We don't desperately need you to do us a favor and bless society with your children, despite the fact that every parent seems to think we do.
In any event, your logic is flawed. A person can easily be a net contributor over a lifetime without having children. And someone who has children, can easily be a net drain even after attributing some of the costs/contributions of the children (which may well also be negative).
They aren't prevented from coming to the United States by people having children, they are prevented from coming to the United States by US immigration law (either because they are individually undesirable, or because they exceed the hard total or per-country caps in various permitted categories.)
So, relevance here is missing.
That being said, there should be a "leave" option for parents adopting children as well.