Like you could almost take him at his word that he really just wanted to make a better world until he was faced with total defeat and the mask came off
If he didnβt laugh maniacally and just said βoh rats you got meβ then that element of his character wouldβve been totally lost and youβd be left thinking βah dang he just wanted to make a better world and he lost. RIP the good guyβ
It makes sense too, because in the beginning Light says it sounds cool and important to be a shinigami, also after using the DN you go to neither heaven nor hell, so, makes sense he'd become a shinigami.
