Having kids is great.
Don't have any myself.
And I Love the family dynamic in some superheros like fantastic4(the book) and The Incredibles, First Family(from Astro City book) and Captain Marvel books.
I guess the argument is us Fan Boys are still waiting for an Ultimate Superman movie a la Batman Begins, Spiderman that take almost 90% of it's fundamental direction from the books. One only has to look at the Spidey3 trailer to know that indeed Raimi read 'Saga of the Alien costume' and 'Spiderman vs. venom' from late 80's early 90's.
A kick ass Superman movie with drama, intrigue and action and villains on par with last nights sneak preview (spidey3)fight between Harry and Peter is what we want sans a Superson.
Chris Nolan could probably (if he wanted to) pull off a kick @$$ Batman sequel with Robin but he says he won't and most fans are fine with that because it's really Batman we want to see. Same with Superman (worse actually) because Super Jason has never appeared in Supermans history before. He goes into the bargain bin for pointless 'made up' characters along with Nuclear Man. An unnecessarily puzzling element that redirects superman further from his core essence. He doesn't need a son yet.
If Singer refuses to look in the books (where the character was born), how can we trust him to interpret how Superman would act as a father?