Right. It's not like when they change the JLA's history every year and then they have to adjust a ton of storylines. And it's not just that there are a lot of characters...it's that a lot of characters have long, involved and intertwined histories. Have Superman show up after the JLA has formed (as the change happened) and lots of things spin wildly out of that.

And DC insisted on poking the rough patches (which led us to 'needing' Zero Hour and so many other events to continually keep trying to 'fix' continuity).