One of the most common complaints against changing Peter Parker’s marital status in One More Day was that other superheroes have spouses and children, so this should be appropriate for Spider-Man. For brevity’s sake, I’ll ignore the critics and creators who didn’t think it was a good idea to give Batman a kid, or have Superman marry Lois Lane. Comparing the directions of other franchises often demonstrates why there are things DC can do with the Elongated Man that the people at Marvel just can’t (or shouldn’t) do with Spider-Man.
When Bruce Wayne’s son Damian appeared in Grant Morrison’s first Batman arc, it did lead some to ask why it’s okay for Batman’s long‑lost son to return, but not for Peter to be reunited with his daughter in the Spider‑Man comics. One reason I had no problem with Morrison writing a sequel to "Son of the Demon" was that the storyline it referenced was an excellent Batman tale, deserving of its position in a list of IGN's ten best Batman stories. Anyone confused about the origin of Batman’s son can buy an accessible, well regarded and self-contained TPB. The clone saga fails these criteria.
Prior to Flashpoint, Superman had become the epitome of the successfully married superhero, though the best‑selling and most acclaimed Superman comic book story of the last few years (All‑Star Superman) featured the character when he was single. After the events of Superman Returns, I was expecting Lois and Clark to have a child, but there are a few differences between DC’s most recognizable hero, and Marvel’s flagship character.
Plus, DC gets to do universe wide retcons every few years, an option Marvel hasn’t resorted to yet, so they’re able to expermient in terms of radically shifting status quos. Many of the most successful DC books (IE‑ Kingdom Come, The Dark Knight Returns, New Frontier, The Golden Age, Justice, Whatever Happened to the Man of Tomorrow?, All‑Star Superman, and Superman: Secret Identity) aren’t set in the current DC Universe, you could easily make the case that DCU books just aren’t as important as the Marvel Universe books.
The Flash briefly followed a superhero with two young children. It was a monthly as opposed to a flagship almost weekly, but it was used an example of a successful superhero family title when that aspect has been the direction of the book for less than six issues. The only reason Wally West returned (wife and kids in tow) was that the decision to make Bart Allen the lead proved unpopular (much of that could be attributed to the previous creative team) and the staff wanted to bide time until Barry Allen’s eventual return.
The individual mostly associated with the Flash persona, Barry Allen was killed off before he was replaced by his sidekick, establishing that the Flash’s private identity isn’t as important as Spider-Man’s. Spider-Man doesn’t yet have a sidekick as compelling as Wally West, although a better character would be necessary to justify the replacement of Peter Parker. And they still brought back Barry Allen. And then made Barry single.
Other DC Heroes
Other DC books also demonstrate the disadvantages of permanent romantic relationships in a serial format. Ralph and Sue Dibny were generally part of an ensemble, and often minor players in the DC Universe, until tragic developments in Identity Crisis and strange developments in 52. Ray Palmer and Jean Loring’s romance also came to a nasty end. Donna Troy and her husband were supposed to demonstrate that a happy marriage was possible in the DC Universe, until he got killed off, along with their daughter, following a messy divorce.