Many suicides are impulsive. I have no doubt that many suicide survivors feel they acted rashly and are grateful to live. Other suicide survivors may improve their lives after the fact (spurred on by enforced no suicide, or family helping them, or just seeing their actions affect others, whatever), or feel a weird sort of gratitude to those who put in effort to save their lives. People who are prone to defeatism might rationalise it into optimism to be able to psychologically cope. Just some examples of the reasoning I've seen.
Studies have found that impulsive suicides (which is admittedly a bit of a nebulous term in suicidology) make up a fairly significant proportion of suicide attempts, and they (rather understandably) tend to fare better medically from their attempts, especially when access to particularly fatal methods is restricted. Their circumstances tend to be better statistically and their ideation not always as severe. I have no doubt many of these people have become very desperate but, when encountered with how miserable a suicide attempt is and given a chance to re-evaluate (maybe their family show sympathy, maybe their suicidal symptoms are alleviated long enough to enjoy things temporarily, maybe they are even given successful treatment for their problems), they stick it out until it gets better enough for them. Cynically I think many just rule it out and do a lot to rationalise what's acceptable because the outcome - that they really go through with suicide again - is untenable to them, a real last resort if anything, but that is true of much of humanity.
A person who attempts suicide because his fiancé left him may start to get over it and see that life is livable without her after some time, but he still is forced to work miserable jobs, probably until he dies. But he is psychologically resolved to work those miserable jobs and not deeply suicidal in a way he can consciously recognise because of it; he just uses it as suicide fuel when something really pushes him to the limit, like being without one of the few things that made all that hard work worthwhile. Did his situation change?
Of course, there are outliers. Some impulsive suicides are part of a pattern of impulsive suicidal behaviour motivated by chronic suicidality, e.g. in the context of some mental illnesses. Of course there are impulsively suicidal people whose lives will not get better or don't get better. These people aren't necessarily glad to have lived. I imagine there are plenty of people who aren't happy but believe they have to get on with it now, or are scared to attempt again, or don't know how to help themselves, or can't even admit it to themselves because the alternative would be suicidal desperation. Never forget that there are many people who believe in destiny.
I will tell you something that affected me greatly after an attempt I made to drown myself in the ocean four years ago. I failed, and I had been out in the water for hours. It was winter. I was miserable and I clearly looked very 'wrong' - nobody goes out for a winter swim at 4 AM in their nightclothes. At the time I had given up, the sun was coming up and people were coming to walk their dogs by the beach. Now part of what had driven this attempt was violence in the preceding days, total isolation and despair, and the knowledge that all my life, people had treated me terribly and would likely continue to do so. But at this point I was not completely jaded.
Every single person stopped to ask me what was wrong and if they could help me. It was the bare minimum expression of human decency. A few people followed me to ensure I really did not want help. I had never been acknowledged so often by strangers before in a genuinely concerned way. In fact, I had generally been ignored and laughed at by strangers. I was completely vulnerable to this kindness. I got myself out of the terrible situation I was in.
I told this story because I expect the experience might be a little similar for the recent survivors. Any kind treatment given to them post-attempt might be some of the first real care they ever got, or the most they ever got at once. You have a physical high from survival* and a knowledge you have to get through at least the few days. You are vulnerable to anything and your brain does what it has to do to cope with the realisation you're stuck living a bit more. Six months down the line, when everything's gone back to normal, or six years, when the high of survival has worn off, and most importantly they're no longer being surveilled, it might mean a lot less to the person.
*Many people who go through life-saving surgeries also experience this post-surgery euphoria.
Anyway, we can defend our right to choose - others choosing to live should not diminish our choices if they're well-reasoned and we can understand why others would make that choice enough to reject its scope, or if we reject the premise.
edit: Also, yes, those stories are amplified by pro-choicers, and I imagine their emotional nuance is simplified in the process. It's worth noting there are many pro-choice emissaries who went through some of the processes I described themselves - they failed and are defending their choice to live, both internally and externally. They may prioritise some of the pleasure they've since experienced as better than all the pain they went through, or ignore their immediate anger and despair because in the long term they ended up happy, etc. Many of them are terrified that they might have succeeded and want to save others from that, whether they assume everyone is like them or they just target those who are. Sometimes they view it as a calling. Other times they are affected in other ways by suicide or see the potential effects of it on their loved ones, so they go and assume everyone else is like them.
