TL;DR: Money. Additionally, companies should provide more/longer maternity leave and flexible working hours. So, ultimately it's just reasons why anyone would

TL;DR: Money. Additionally, companies should provide more/longer maternity leave and flexible working hours. So, ultimately it's just reasons why anyone would leave a company. Either the pay is too low, or the job is too onerous and doesn't fit into a life that isn't 100% based on work. Personally I've always been a bit confused by maternity leave because it seems like common sense to just allow sabbaticals in general for any reason, but we're not there yet it seems, so maybe it's a good first step.