Disclaimer: I'm a feminist, maternal AF father, so that's going to invalidate what I have to say (a little bit). I quit my job for my daughter's pre-school (kindergarten in Queensland, Australia) year (so she was turning 4 in May) and was her full-time (weekday) caregiver (and I loved it). I read this book around that time. It resonated with me.
Fast forward, that beautiful young woman is now a GAD+ADHD diagnosed (and medicated) 15 year old and doing okay, all things considered. I'm now full-time studying psychological science and counselling, so it's interesting how some things loop. I was recommending this book to a fellow student and new mother and went rummaging for online opinions about it, and here I am.
I get the sense there's an element of "shooting the messenger", which is easy to do when it's a man, and he's saying something, as has been pointed out elsewhere here, that perhaps some people don't want to hear...
I agree, that once a child gets to toddlerdom, the physical dependency on the mother (as opposed to the father, in a heteronormative relationship) wanes, and it's the perfect opportunity for some gender equity. I'm grateful for the role I was able to play in my daughter's formative years. I'm also glad I was able to do it free of the demands of work for a year.
I loved the book, it resonated with me, made sense, and I don't think there needs to be any shame in putting your own oxygen mask on first and choosing your own sanity and well-being. If that means returning to work, so be it. Ideally your child's primary caregiver could then be the father, or a grandparent, or some other stable, nurturing adult. I do think depending on the choice of long day care, this comes at some developmental tradeoffs, that don't necessarily rear their heads until later.