First of all if u got pregnant in the first place u where not using your head .If u are having a child but u are not a full grown adult mentality than u dont know the first hing a bout child safty or how to change a dipper or even make bottle.
If it becomes mandatory ( which it probably will, due to Trump) most families will lose their kids and there would be too many orphans in the world. Another reason is mothers have instincts and the "teachers" are teaching in their own opinion and you could ask for advice from your parents or future grandparents
No, I do not think that parents need to take parenting classes. Learning to become a good parent will happen naturally over time, and with the right help from other parents or even grandparents I think that all parents can be good caregivers and raise their children to be moral and ethical.
All children have different needs. A Parenting class only teaches the basics of parenting. So if your child had turrets,or ADHD, parents still won't know how to take care of their child. So parents need to know the risk before they have a kid, and how to treat their child with support, and care in balance. So you choose, know the risks and learn,or take a class for a while, just to learn things that an ordinary child needs. Every child is unique and special in their own way. Parents need to know how to take care of their child in their own way. Such as needs or education.