When City of Heroes was first bandied about, I had an idea of creating all of my favorite super-characters, that I've played under Villains & Vigilantes, Aberrant, GURPS Supers and even Mutants & Masterminds. After the game came out, I realized that most of them weren't really doable, and even if they were, their backstories didn't mesh really well with the CoH backstory.
Instead, I ended up making all new concepts, based on the setting, tied to the Circle of Thorns, or Sky Raiders, or Devouring Earth, or Skulls.
Ultimately, I'm playing in someone elses City, not my own setting, so making a character who's the son of a diety, or a shapeshifting alien, or a sentient ball of energy, and has enemies among the rakshasa/unseelie fae/atlanteans is pretty pointless when there aren't any available as NPCs...
Unless they were to create a 'make your own zones, costume sets, missions and powersets!' expansion, it would be kinda silly to make any of my traditional tabletop RPG superheroes, since this world / setting / system isn't the one I made those characters for, nor was it meant to be, nor was it sold to me as such.
I know of plenty unauthorized JLAs... I just remember hearing about an actual 'with consent' tribute SG, and wanted to see if anyone could verify if it did in fact exist. I didn't need to be told that unauthorized JLAs get shut down - that much is obvious.