I think its a load of self indulgent, moaning negative bollocks, frankly.
Ive seen this woman write other articles about how she's worried she'll have noone to look after her in her old age due to having no kids as if thats the only reason to have them.
I have children and I have never once slammed the phone down on a friend, childless or not. I've always been there for my friends and supported them even when my children were small. I was my best friend's bridesmaid when my youngest was 6 months old as an example.
The most flaky friend I have ever had in my life was childless - he used to let me down constantly at the last moment, often when I had booked and paid for child care or when I had invited him round for a meal and was just taking it out of the oven. I'd get the inevitable "oh so sorry darling, I cant make it now, something has come up". After several decades of this I finally had enough and we are no longer friends.
As for assertion that I should be putting my friends before my own kids - WTAF? what does that even mean?- I have a parental responsibility to look after them, I dont have a legal responsibility to look after my friends because they are all capable adults. I have never once thought my life was "more important" than anyone else's - I might have more responsibilities but that isnt the same as thinking "I am SO damn important".
She sounds like she has a huge, unpleasant chip on her shoulder and I dont appreciate her generalising about parents as if they are one huge monolith. I am quite sure she wouldn't like it if I did that about people without children.....