Actually "The People" do decide, they have a choice to have an abortion or not to have one. So yes the 10th amendment is being followed perfectly.
It is not "whatever" it is a reflection of your approach to the topic and debating. Quite embarrassing actually.
Point out one reason why it is illegal. Everybody is allowed to have his own standpoint without being scolded. Abortion is needed when the kid is expected to wrongly grow up or the parents can't afford his basic desires. I know it's grossly depressive to kill a kid before he is born but this may be decided when inevitable. I condemn a murder of anybody if the reason for that is inappropriate but it's sometimes much better than the tortures kids have to suffer from while growing up. There must not be a law that prohibits this action ! If there is,the right for a free opinion is automatically revoked.
Just like illegal immigration in the USA. It's easy to make a new law. But it takes more effort to ensure that it is enforced. When this does not work, all too often people think the easy solution is just to make more laws and mandate harsher punishments, but this is often ineffective and/or unfair.