The only reason Kishi's should have given for Orochimaru still being around is that Orochimaru literally can't be killed by any conventional means, which he can't by the end of the series. That's it. Naruto and Sasuke keeping him around otherwise is grossly irresponsible. Konoha should have an entire team researching ways to kill the bastard for good. They are making the same mistake Hashirama did with Madara. If Hashirama didn't drag his feet around regarding Madara, much of the events in Naruto could have been avoided.
