What's so special about childbirth that the base instincts of a woman who's just given birth should be revered and given precedence over everything else, when that's not the case elsewhere in life?
Because she has just gestated the baby for nine months and then given birth, both of which have significant physical, mental and emotional impacts.
When any parent or parent in law (or, frankly, partner) has risked permanent disability or death and gone through the often quite extreme process of giving birth - whether vaginally or via major abdominal surgery - then their needs and wants have equal weight.
I am baffled by the minimisation of pregnancy and birth and the view that it is more reasonable to ignore the wishes of the person who is recovering from pregnancy and birth, who may be trying to establish breastfeeding and form an immediate bond with her baby, than to do likewise and ignore the wishes of non-immediate relatives to not visit her and meet the baby on their own preferred timetables.
I'd go further and suggest that the person who has just done pregnancy and birth actually has the right to be a little bit selfish immediately after giving birth.
I'm the mother of two boys. Neither my mother nor my MIL would have dreamed of suggesting their desire to meet my children was more important than my desire to recover quietly, without visitors and without having the baby removed from me. Neither sees me as a walking womb, you see, whose function is complete once the baby is removed from her body and can be safely ignored until the next grandchild is incoming.
As it happens, the question didn't arise as we live quite distant from all family.