I very much agree! If we were to talk psychology, I would say such behavior could be called projective identification. Meaning, its often self-hate repackaged and plastered onto the image of the collective human race, by pathetic nobodies with the emotional intleligence of a rock. But I think that you are fighting illogical, defensive behaviors (speaking of deeper inner torment) with systematic, objective philosophical logic.
Anti-natalism is, in the true or pure form, an objectuve judgement of morality and a solution forward way of thinking. I believe there is a widespread misinterpretation on the internet, becaude ant-natalism CANNOT co-exist with a disdain for abortions. I'm certain they dont even know what the word properly means, and - like toddlers with mommy's keyboard - just repeat the fancy, impressive long words they saw once to mask their inept self confidence with grandiose and overstated ideological sentiments.
However, misanthropy is a simple opinion, and not always held by anti-natalists. Individuals claiming anti-natalist affiliation and talking of abortion as a negative are not anti-natalists in any sense whatsoever, you are correct. But they are stil misanthropes - actually the very definition of one. I say: let them call themselves misanthropes, let them tell the world with amusing naivety that they are a unlikeable, sordid small minds. I like to think misanthropes against abortions want people to live, just for the sake of suffering, in some twisted sadistic way. They call themselves anti-natalists to hide what they trully are: rudely negative and emotionally underdeveloped young men (they TEND to be, one must be honest). Their claims are not strange, no, they are downright stupid in the simple sense.
It is still so strange to me thst misanthropy has been turned into some edgy, superior idea when the word itself has traditionally been applied to describe loosers who fail to contribute to anything worthwhile, whilst rotting away in their poisons of simultanious self contempt and poorly masked illusions of granduer.
I like what you mention about contributing to making human life one of reduced harm because birth is a torture. But that leans into humanism or more positive beliefs. Anti-natalism has always been intertwined with the pessimistic schools of philosophy. Now, let's not even get into the gross butchering of the term "nihilism." I shudder to think of it.
I agree the inconsistencies are vile and turn original ideas into vapid and banal tokens of shallow self contempt of the author. I always laugh at such people because of their tendency to take themselves so seriously, which to me comes off as a joke. You cannot, however associate anti-natalism and philanthropic beliefs for reducing suffering .anti-natalists are convinced your life is doomed upon birth of your conscious, and many believe only in collective neutering or mass extinctions of the human race.
I should note: the use of derogatory langauge here is to emulate the behavior of the individuals andcollective trends subject in the topic at hand. Additionally, while I impose a strict adherence to definitions I am neither nihilist or anti-natalist. I believe there is good in humanity, trully, and inexplicably so. Though, I do admit I am a failiure at optimism as of now.