You're trying to defend this practise by suggesting it's 'only the most toxic workplaces', but that's not the case. Given two candidates who both have 5 years experience but one has a gap of a year to raise a baby, lots of companies will chose the other candidate. Talk to parents. Understand the problem. Companies assume that if you've taken a year once then you'll probably do it again if you have a second child, and consequently they avoiding hiring you. Don't be an apologist for those companies that do it.