for those spouting 'you should've used protection' or 'don't have ***' and all that, sure, fine. but most women and young teens do. people are going to ****, it is a biological fact. it is inevitable. and that is their choice in the matter just as it is your choice to to stand against abortion
should they be more educated and seriously weigh the consequences? some should, but that's generalizing and factoring out the fact that some are very well educated and are very aware of the consequences. it's ignoring the fact some do use extra prevention toward pregnancy such as shots, pills, and whatnot. lots of women do those. condoms are about 83% effective, pills are around 99%. and some use both. what do you say to these women? they want to ****, but they very clearly don't wish to get pregnant? tell them to not ****? tell them that they don't have the right to do as they please because they're murderers? guilt trip them until they learn their lesson? never **** their boyfriend again unless they actually want a baby? it's ludicrous
then, yes, you're correct: there are the irresponsible ones that makes you feel righteous. and some of these are horny teens, misguided women, college students that don't weigh the pros and cons. but: what if they can't raise the child properly? would you rather them give birth to something they can't even give shelter to and proper emotional support? would you rather give them an emotionally unstable life? and if they don't keep the baby: would you rather put them through the adoption process--force them to go through months of stress, disrupting their entire life, their entire future--only to give the kid to strangers (or close family) that will take care of the kid?
what does that do to the very young, irresponsible mother? would that not be emotionally traumatizing?
if you're for the kid's rights: what is actually honestly best for the kid? what if these mothers are unintentionally neglectful? because they have no clue how to educate themselves? because they don't know what a child really requires?
you've basically given the kid the gift of a shitty life? what then?
morally it's a tricky thing for both the mother and baby, scientifically it's not. there's far too much gray areas to determine what's best for the kid without hurting the mother and vice versa