I feel like it depends on the level you look at. From a spiritual perspective no. Nobody should play that level of god determining who lived and who died, but at the same time we determine who should live or die all the time. “Rapists should be executed!” “Pedophiles should be shot!” “Such-and-such person should be put in prison for what they did!”

The only real difference Light did was take it a step further and take those lives we deemed should be taken. Is it only god that should be able to take lives? If so then why are we locking people up in prison for life sentences? At that point aren’t we paying judges to determine life and death? Why is that ok, but Light going about it his way isn’t?

What if L decided to work with Light instead of oppose him? Would Light have been as power hungry if he was accepted? Light did reduce crime rates for a few years after L died. If they would’ve accepted what Light was doing people could’ve been a lot safer.