I guess I reflect on my experience - I was fortunate, my husband had two months at home with me when our daughter was born, and then flexible arrangements with his employer after that - it helped create a great bond between them, and, I think, helped keep my mental health only at "mild anxiety" rather than "crushing PND" level. And was enriching and delightful for him!
And also because I want a world where becoming a mother doesn't automatically make education, work, or other aspects of life nigh unto impossible, and for that to happen we need it to be easier, not harder, for dads to take an equal share in parenting. For a while there my husband and I each worked three days a week and had really very equal parenting, and we had others around us talk about us having found the "holy grail" of work-family balance. It wasn't perfect (nothing is) but it was a darned sight better than me being trapped at home while he slogged his guts out.
A world where we idolise work as the point of our existence is unhealthy in so many ways; we need to create a culture where we work to live, not the other way around. A world where anyone needs to work double shifts or multiple jobs out of the need to survive (not from desire, and even that should ideally only for a short time) is, imho, wrong.