oh they tried to kill them. well i guess that excuses everything.
if its "needed" how come killling off evil sociopaths like danzo isnt "needed"? why did itachi just let him run rampant on innocent people? why did he do nothing to even try to stop orochimaru? or kabuto? does itachi only behave intelligent enough to defeat enemies when hes ORDERED to?
Wow. You're unfounded Itachi hate blinds you so much.
Danzo didn't go after innocent people, he went after missing nins and people who threatened the village. That and if Itachi killed Danzo when he had the chance, the next shinobi war would have erupted. During a time when the Uchiha were suspected for the Kyuubi attack in the village, it wouldn't have helped if an Uchiha killed one of Konoha's elders.
Upon his first encounter w/ Oro, Itachi didn't have intel on him, Oro had intel on Itachi. All Itachi knew was that Oro was a missing-nin, it was Itachi's first day in Akatsuki. Is it Itachi's job to kill every single missing-nin in the Naruverse, even the ones he knows nothing about? No, not at all.
Later on, killing Kabuto/Oro would be impossible unless those two approached him. They never stay in the same hideout and were always on the move. That's why Konoha and all the other nations that were spending years on trying to find them couldn't.
