There are other writers that have given us Catwoman-free runs, and I don't have a problem with that, because it made sense to leave Catwoman out. Why would you need to reference Catwoman in the Scarebeast storyline, or the Orca story, or Under the Hood?
Morrison, on the other hand, wrote a run where her absence is glaring. Batman finding out about Talia and Damian... a reference to Selina would have been nice, certainly, but not mandatory (mind you, his writing of Batman's love life in that arc was Epic Failure anyway). More egregious is the way she (and the rest of Batman's extended family) got snubbed in RIP. Batman's missing, presumed in extremely serious trouble, and there's gangs of dangerous badguys running roughshod over Gotham. Who's the Cavalry? Who gets to help? Not Catwoman (who lives in Gotham), or Batgirl, or Spoiler, or Oracle, or Huntress, or even Onyx. No, instead of any of the people that are closest to Bruce, the day gets saved by people that had to fly all the way from Australia, Argentina, and England. When Bruce is in trouble and the guy from Australia shows up but Catwoman doesn't, that's a problem. But even that would be forgivable, except Morrison follows it up immediately with a story replaying the important moments in Batman's life (or Grant's idea of what's important, at least). And Selina gets what's above, while Morrison gave plenty of room for his own stuff (Thogal, Damian, The Ten Eyed Men, RIP, Final Crisis, the Hurt flashback), and about 3 pages to go into the great emotional impact of Batwoman. Catwoman fares about as well as Ace the Bathound in a retelling of what's important in the story of Batman.