Zamasu and the Super Dragon Balls

[SuperSalt]

Hello there!
I was wondering, why didn't Zamasu just use the Super Dragon Balls to kill all mortals, and complete his zero-mortals plan? There supposedly is no limit to the wishes, and it could've saved him the hassle of killing everyone himself.
Perhaps he wanted to do it himself, to make sure it was seen through? Or maybe he didn't do it because of his sadistic nature?

What do you guys think?

[Doctor.]

Definitely think he wanted to savor the killing himself. He could have tried to wish for the Gods to die, though, I think that was an oversight on his part.

[SupremeKai25]

He was mad and sadistic. Wishing for all mortals to disappear instantly would have meant certain victory for the Zero Mortals Plan, but wouldn't have been nearly as entertaining and amusing for him. He wanted to take his time and make them suffer. He thought that the sinful mortals did not deserve a swift and painless death for their heinous crimes against the sacred laws of the Gods.

In the words of Fused Zamasu himself: 'A weak God incapable of wiping out evil is worthless'. Zamasu also wanted to prove himself as a worthy and powerful God by personally eliminating all evil (mortals) in the world of Gods. It was his duty. And from his perspective, his actions were driven towards the rise of a perfect world that would never be sullied.

[Lord Frieza]

Probably the dragon will not grant such a wish if it's creator desired it not to be able to do so.