They learned their lesson and this time around they are throwing nothing out. They realize now that the fans take it as a personal insult when they do.
So it all happened in one form or another. Everything. The pre-crisis stories and the post-crisis stories.
Good. There was never any reason why it shouldn't have all been canon, really. All they had to do was say, "Now we're going to focus on an Earth you haven't seen before" instead of "the Earths you liked never existed and your old comics are moot." They could still have started all the flagship titles over at #1...I think it would have been fun watching history repeat itself on a new Earth (I know I enjoyed watching Earth-Prime get a Superboy, for example), but when you throw out earlier versions altogether, you're putting an awful lot of pressure on yourself to come up with something actually BETTER. Which in almost every case, DC has been unable to do.
This is a hallmark of good writing - this is what fans have been claiming is a sign of good writing and have been clamoring for. Fans spent a lot of time saying that "hard reboots" which "sweep everything out the door" are just lazy writing by bad writers who don't want to be bothered to know old continuity or to have to think.
It's more than that. It's a way to tell the same stories over again and pass them off as your own. Byrne tweaked the Lori Lemaris love story and Bizarro's origin...he did NOT create the characters or even recreate them in any major way. And his take on Superman's origin, while certainly different enough to cheese me off, was not nearly innovative enough to qualify as anything more than an edit to the Seigel and Shuster version. And yet you just know he got paid tons more than Jerry and Joe ever did just for basically taking their ideas and doing a glorified edit.
I for one am sick to death of re-tellings of the origin story, and consider them the height of laziness. What I wish is that instead of going after Superboy and "Smallville," which are full of characters Jerry had nothing to do with, the Seigel family would instead sue for royalties on every telling of the Superman origin, since that tale is definitively, demonstrably and substantially
his work, and despite all the tweaking over the decades remains very close to what he first wrote. DC should be forced to pay the Seigels through the nose every single time they retell the story. I'm convinced that's about the only thing that will stop it.