User blog comment:New Dalek Paradigm/Ninjago Rebooted for 2014 - My reaction/@comment-5413035-20131127151122/@comment-5413035-20131129232420

Greg Farshtey has said it was discontinued because, though it was still doing well, action figure set sales had been dropping since 2004 and LEGO wanted to take it off market before it had chance to fail, so if they someday want to bring it back, retailers will see that it was successful and want to stock up on it.