wingsandsword
Legend
And the next day no one is raped, no one is murdered, no towns are burned to the ground. Do you really think the good done by evil creatures outweighs the evil done by evil creatures?
Why would there be nobody raped, nobody murdered, no arson? Neutral people sometimes commit evil acts. Also, people change alignments, it's part of the whole "free will" thing, and you think that maybe 1/3 of sentient lifeforms dropping dead suddenly won't drive some neutral or even good people to evil? Like someone who saw his parents die and wasn't on a dark path. . .until he had to turn to a life of theft to survive when the breadwinner for his family died, or someone who swore vengeance against the person who killed his parents/wife/children/best friend.
What about the chaos and mayhem caused through society at so many deaths, like dynasties falling, armies being decimated, important guilds being massacred, do you think this on it's own wouldn't do huge damage and cause much suffering? It's not just waving a magic wand, everybody with an Evil alignment drops dead and now the world is a happy sunshine and fairy dust place because there is no Evil anymore.
Being Evil is not a capitol crime in and of itself. In fact, I'd say that in terms of committing actual crimes, you'll probably find more committed by Chaotic Neutral people who just plain disregard the law and commit occasional evil deeds (and occasional good ones) but not enough to have an Evil alignment, than by Lawful Evil people that are dark-hearted but stick to the laws of society (mostly).
Even then, you're saying it's actually not evil to slaughter millions of people instantly just because their alignment detects as Evil, without regard for any acts they have actually taken that are evil? As was pointed out, a merchant who regularly shortchanges by a few copper his patrons might could have an Evil alignment (especially if he also regularly commits other very petty Evil like maybe spreading false rumors about his competitors), that could get you a LE or NE alignment if you do it often enough. Alignment is a rough gauge of law/chaos and good/evil in someones intents and deeds, and not a very just way of deciding who lives and who dies.