Didio dislike (not hate) multiple sidekick generations, because of how authomatically aged the Satelite Era crew, he doesn't dislike the characthers thenselves, just what they represent, but they have a big enougth fanbase to keep around and try something with then and why he doesn't kill then, is the same with Dick or more specifically Nightwing. I'm pretty sure that if he could have his way, we pretty much would be with Dick as Robin, Wally as KF and none of the 90s or 00s sidekicks would still be around.
Althougth i think than this second chance is more Bendis having a lot of pull, he is big enougth to have creative liberties.