Maybe we wouldn’t either. Or at least some of us. And this does not contradict our views because anti-natalism is not necessarily a moral view against life but against the creation of new life. The question at stake in anti-natalism is not whether it is moral for you to continue living your life but whether it is moral for you to force others to live the life they will have. So if anything, in order to justify reproduction people somehow have to know in advance that the answer of the people they produce will be that they would prefer to exist.
But in fact this is also not enough because there is something very problematic about this claim. When people think about the possibility that they did not exist, they do not think about the possibility that they never existed, but about the possibility that their current existence would cease, and it is very possible that they would not want to cease their existence. But of course this is not what would happen if someone never existed. If you had never been created, you would never have existed, and therefore you would not have experienced anything including non-existence, the possibility of not existing, and certainly not ceasing to exist when you already exist. The meaning of the choice to never exist is the cancellation of your existence in retrospect, and along with it every experience you have ever had. Usually people think about this state as if they are “losing” everything they have experienced and some would not want that, but there is no such state of loss because there is no one who loses anything. If you never existed that means there is no one and there never was anyone who is you. It’s not that you’re experiencing any loss. Choosing to never exist does not detract from your existence. If you never existed the question about your life would simply not be relevant because you simply don’t exist and never did. The question of what would be better for you in the context of never existing is meaningless because those who never existed have no preferences. There is no better or worse situation. The possibility that you would not exist has no relevant meaning for you when you already do exist. It is irrelevant to ask whether you would prefer not to exist because it is not an option. This is not a situation to be in. It is not an alternative to existence. Someone can only exist. If not created there is no one. And if there is no one, there is nothing that is better for that no one. In order for something to be better for someone, there has to be someone and when there is someone then there is already existence and when there is existence then there is no non-existence.
This mistake is completely understandable and it stems from the fact that it is not possible to imagine non-existence because it is a state in which there is nothing and it is impossible to imagine a state that does not exist. One can only imagine existing things or their absence in existing situations, meaning, imagining an existing situation in which something did not exist, but it is not possible to imagine non-existence. And it is clear and understandable because there is nothing in non-existence. But that’s why it is not bad either. There is nothing to be afraid of and there is no reason to think that it is better to exist than not to have existed, since there is no such state as to not exist. You can exist or not, but you cannot be in a state of not existing. Therefore, the claim that you prefer to exist than not makes no sense. There is no second option. You can only exist. If you never existed then you never existed and therefore it makes no sense to attribute preferences to you. Existence is not better for you because for something to be better it has to be in relation to something, some alternative, and there is no option of non-existence. Non-existence is not an alternative. The person who claims that s/he would rather not be born is actually claiming that s/he would rather not experience her/his existence because her/his existence is bad for her/him, not because the alternative is better in her/his eyes. Someone like that basically says I’d rather end my existence or the option that it wouldn’t have started at all because it’s bad for me. That is, it is a statement about the existence of that person, not about non-existence. You can say that you prefer your existence not to be stopped or that you are glad that it started, but not that it is better for you than non-existence, because that is meaningless. If you never existed you wouldn’t care that you don’t exist. And you wouldn’t want to exist either. There was just never you, period.
Most people claim that they wouldn’t prefer not having existed because they imagine non-existence as a negative thing whereas it is nothing. They think about missing their current life when they wouldn’t miss anything since they never existed. Non-existence is not a mental prison of floating consciousnesses begging to exist. Non-existence is nothing.
This misunderstanding of the option of non-existence causes many people to think that it is better to live a difficult life than not to have lived at all. This is despite the fact that those who never lived do not missing anything, and the meaning of not missing anything is not in the valued sense, i.e. because life is bad, but in the literal sense because that person never existed and therefore cannot miss anything. No one can be harmed by never living even when if they had lived, it would have been a happy life. On the other hand, anyone who lives a very unhappy life is hurt by it. And unhappiness is always a possibility when creating life.
In conclusion, as explained so far, the question of whether with all the difficulties in life, if I were offered to never exist, I would choose this option, is not relevant in itself, and even if it were, it is not relevant in the context of creating people because this should not be our decision, and if anything, it is a question we shouldn’t ask ourselves but those who we create because it should be their decision. You can’t ask them and they don’t get to decide, and that’s exactly a big part of the problem with reproduction.