Lots of great points in the comments. But I think so far no one has really addressed your core complaint head on, which is why society tolerates a double standard here.
Parents get a pass because they are supporting more than just themselves… It may appear that the parent who is getting a free pass is pulling less weight, if you look at this exclusively through the lens of comparing contribution to the company’s productivity. But if you expand that lens a bit, you see that raising a child is also work to be valued (which you benefitted from yourself, btw). Frankly, a company with a work culture that considers its social responsibility to the community beyond merely spitting out products is a really good thing.
If you are ok with the double standard of handicapped parking, you should be ok with this too.
The scientific process derives consensus from not observing what is expected in a theory, rather from repeated failure to observe counter examples to what is expected. This is the whole point of “reject the null hypothesis”.
Stated more plainly, a scientific theory is solidified when you put yourself in the shoes of your own fiercest critics, and attempt to question your own idea (in good faith) and fail to observe any evidence to substantiate that criticism. A scientific theory, is then put under that scrutiny for real, and gains consensus when others fail to observe any counter examples for themselves.
So to answer “what to look at”, the answer is always, what would your competition look at to try to disprove you? Then look at that, to see if there is anything of substance to discredit your own idea, and save everyone the time and your embarrassment in case there are easy counter examples.