While we're at it, why shouldn't any prospective employee with a health condition that might require extensive time off be required to disclose that? And, since people aren't often the best judge of their health conditions and the impositions they'll make on future employers, perhaps it'd be better if we all just disclosed our complete medical records along with our job applications.
Well, philosophically, at some point yes. There should be some level of personal responsibility not to sign up for a job that you don't intend to do. I don't think being required to provide detailed medical records is reasonable, a good faith, optimistic best-case is enough for me.
And while you might see pregnancy as equivalent to having a medical condition there are actually a number of fairly important differences. For example, in the modern era, pregnancy is more controllable than illness. Quite a number of people enthusiastically plan on it. Those aspects, intent and control, are important for determining who should bear the cost. The cost should not settle on an unwitting employer looking for a new hire.
I have a health condition which causes me to be suddenly absent for a week at a time 1-4 times a year. I absolutely disclose this to any prospective employer because I don’t want them to grumble when it happens.
It points to the state sponsored solution. If a single employer is supposed to carry the burden then they will obviously want to hire young healthy men above anyone else.
Fortunately this is exactly how it's implemented in most European countries: if the employee is not working the employer doesn't pay. The (usually state run) insurer does.
Requiring businesses to pay for someone taking time to care of their children is patently stupid and unjust and there is fully justified pushback against such laws.