Why the hell should 50/50 be the default when most men have never, ever picked up 50% of parenting/childcare before???
They view looking after their own children as 'babysitting' or 'helping', and usually greatly grudge having to do so at any time.
They flatly refuse to take time off work for child sickness or appointments for the kids e.g dentist/hospital/GP/school etc
They don't even usually know who their kids teachers are, what time drop off's & pick up's are, what after school activities & clubs they have and how to arrange/pay for them, they don't know where the kids dentist is, when the next check up is due, or even who the kids dentist even IS ffs !
They have never bought school uniforms or summer/winter clothes for their kids and wouldn't have a clue when new clothing was needed, or which clothes the kids have outgrown.
They don't shop for the groceries for packed lunches and wouldn't have a clue about which kid ate what fgs, never mind what to buy and cook for main meals for the kids !
Yet they think that 50/50 is preferable, because it saves them money ! They STILL don't do the aforementioned, they just leave it for the Mother to continue doing all that stuff, while they either play Disney Dad or leave their kids in front of screens when they have them!
50/50 is simply what Dad's want, because it's a kick in the teeth to the Mother & it's cheap. It's the worst case scenario for the poor kids.