Why is it that kids of superheroes are so often aged via time-travel and other methods? I've heard the explanation that it's done so the superhero parent doesn't seem old, but this makes me imagine them being even older than just having a baby or little kid. As much as I enjoy characters like Cable, I kind of tire of the trend (and just to clarify this question isn't spurred by any recent storyline).
It’s often the case because grown children are easier to write about as active characters in super hero stories than toddlers.