A couple of people have thrown up this argument. But it doesn’t wash, because we’re talking about Peter Parker here.

Cops and soldiers are beyond a doubt heroic, but they are not driven to do what they do exclusively out of a sense of responsibility (or, really, guilt) as Peter Parker is. For them, being a cop, being a soldier is a vocation. Not so for Peter Parker. As Spider-Man, Peter operates outside the law to do what he thinks is right. It’s a calling–and one that is often at the expense of his vocation (whatever it happens to be at any given time.)

And should Peter get killed or crippled while running around outside the confines of the law and enforcing his own personal brand of justice, what happens to that child? Peter lost his Uncle Ben–can he allow the possibility of his own child having to cope with the same kind of loss solely because of his own sense of guilt?

I don’t think so. That’s not the Peter Parker I know.

If Peter wanted to be a cop, or a soldier, then he could easily become one, especially with his powers and his scientific background. But he doesn’t. He continues to operate on his own, because becoming Spider-Man was ultimately a childish decision, a selfish decision, about personal atonement.

Once you become a parent, your child becomes the center of your world. (For those who are arguing this, I’m guessing that you don’t have children–or hoping, at any rate.) At that point, Peter cannot in good conscience put his own wants and desires ahead of the welfare of his child. he cannot be Spider-man if there is any possibility that doing so will cause pain to his offspring.

As some have said, there are plenty of other super heroes. And no matter how much Spider-Man does, people still die, tragedies still happen. We want to see Peter fight on because that is the story that we enjoy–but given this set of circumstances, it doesn’t make any sense for him to do so. Once Spider-Man brings another life into the world, his greatest responsibility is to that life.