WARNING: MAJOR SPOILERS!
Steve gets MePhoneX to permanently kill OJ, Pickle, Nickel, Toilet (heavily implied), and presumably Guava and Soap, was implied to have been brutal enough towards MePhone3GS, has lots of personal villainy towards MePhone4, and attempted to use a lot of the young Light Shimmers' bodies to power his devices. There's so many things backing up how heinous all of these are, and permanent death is not something seen in Inanimate Insanity except when Bow died, but even then, Bow was still able to live as a ghost, and that was when she died when MePhone4 died with her. Killing objects permanently with seemingly no way to bring them back makes Steve Cobs heinous enough for NPE, because whether all of these rely on enough Fridge Horror is up to you to decide, but another reason he may not be a PE is because he does seem to genuinely have honor for MePhone4 and his show, Inanimate Insanity, saying he genuinely enjoyed it and was impressed by MePhone4's capabilities of making some insane challenges that can send objects to space, making magic portals, and a haunted mansion. If this isn't enough to prove that his honor is genuine, he even let Season 3 (Inanimate Insanity Invitational) happen, and this entire scene had him sing so many praises for MePhone4.