He was meant to. IZ was created by Johnen Vasquez--creator of Johnny the Homicidal Maniac--after all, and IZ was supposed to be the type of show where people rooted for the bad guy (i.e. Zim) in that due to the problems of the world (the ignorant & stupidity of people being one), people would want to see Zim conquer Earth. Heck, for the finale, JV wanted to kill Dib off in typical JV fashion (i.e. dismembered and in graphic, visual detail), but due to Nick's family standards--which angered JV--both Nick's execs and JV both chose to end the show prematurely (with JV saying that he'd never work in animation--especially for networks like Nick--again).