Those who do not want to change their past have a valid reason, even if it is a little. However, I think that such people are not open to innovations. Maybe they would have a better life, better conditions. If they lost their spouse and children a few years later, would they think the same thing again?
And this is the thing, isn't it? They assume that the future is going to be the same as the current situation. We as humans are very bad at predicting our future feelings, yet we let them guide us thoughtlessly.