Mercurius
Legend
I personally don't get off on playing evil characters, so wouldn't "go around murdering innocent orcs." But I would play a character that kills orcs that are attacking the party, or even raids an orc cave if it fits the story.I get that D&D is a safe playspace.
But for that reason too, there is no problem if your character is Evil, because the character goes around murdering innocent orcs.
That said, as DM I like to throw in little ethical quandaries. The party is attack by orc raiders, kills them, then tracks their passage and finds a small settlement with starving orc children, mothers, and elders, discovering that the orcs were raiding because they needed food and supplies. Or somesuch. What do the PCs do? Do they help the orcs? Do they leave them alone? Most people I've played with wouldn't kill the village.