I think Joker will go down as one of Morrisons' failures. The man does wonderful stuff, and even the should-be-shitty stuff (like Damian Al Ghul) he generally manages to pull off with a knowing nod and wink to the audience, but sometimes he just fails spectacularly.

IIRC, Arkham Asylum wasn't that great either, and that mainly focused on the Joker too. He overreaches when it comes to the Joker, thinking that symbolism can stand in for coherent character development, and it comes across as merely pretentious tosh I'm a Morrison fan, but sometimes even I realise he's a bit up his own arse at times (please forgive the expression).