Because alignment means all specimens, no matter gender, age or any other factor, are irretrievably and inevitably EVIL!
So it's okay for "GOOD" characters to be murder-hobos!
I always had troubles with that... probably why I binned alignments very quickly and gave the humanoids and others as much variability as humans.
Plus, I find it hard to introduce new folk to the game with the old AD&D monster manual "100 warriors in the lair along with a like number of females and twice that many young". Okay, so.... to protect the Keep.... I guess I have to commit mass genocide then? Where's my D20!
<rolls eyes>
Should have stuck with that name too. Most people could spell thief or thieves (maybe thiefs) at a pinch, but I really twitch when I see someone describing their character as a 'rouge'....