Morals, as has been shown, change with times and peoples
Personally, I think
wrong is a good word.
wrong (adj.)
late O.E., "twisted, crooked, wry," from O.N.
rangr, earlier
*wrangr "crooked, wry, wrong," from P.Gmc.
*wrangaz (cf. Dan.
vrang "crooked, wrong," M.Du.
wranc, Du.
wrang "sour, bitter," lit. "that which distorts the mouth"), from PIE
*wrengh- "to turn" (see
wring). Sense of "not right, bad, immoral, unjust" developed by c.1300.
Wrong thus is etymologically a negative of
right (from L.
rectus, lit. "straight"). L.
pravus was lit. "crooked," but most commonly "wrong, bad;" and other words for "crooked" also have meant "wrong" in It. and Slav. Cf. also Fr.
tort "wrong, injustice," from L.
tortus "twisted."
Wrong-headed first recorded 1732. To
get up on the wrong side (of the bed) "be in a bad mood" is recorded from 1801.
Whatever the moral justification given for genocide in whatever time and place, it is always wrong.