Why do people around me tend to increase their responsibility load (i.e. have children, become a manager, do charity, etc.) while I (30M) try to avoid it as much as I can?

I became a parent because I worked in the school system and taught kids without good families. I used to stay after school just to give these kids a positive influence before they get sent back to their shitty home.

Don't take this as criticism, just trying to understand: What's the logic here? As a teacher without kids (for now), I feel like I'd have more to give to help my pupils if I don't have kids of my own.