Because Nightmare with new art is depicted here: http://forums.mtgsalvation.com/attachment.php?attachmentid=141958&d=1367946965
Makes me think there's a seriously good chance of it getting reprinted in M14. Of course, it's by no means a good card in constructed, but I've always had a soft spot for the scaling flier, even if it doesn't scale particularly well.
Also, this + Kalonian Tusker make me think it's even more likely that M14 is gonna push mono colour. So.... Tendrils of Corruption reprint pls, WotC!