Okay, I'll play as Captain Obvious here. The anti-necromancy stance has a reason. When you're talking in an active thread, it assumes all participants are able to reply, that is, if you ask a question, they're free to choose whether to reply to you or not; if you troll them, provoke them or bite them, they have a chance to snap back; if you're invoking a moderator, it is to deal with a current issue and not wasting their time; and so on.
However, replying to a long-dead thread, in my eyes, is like talking to absent people: if you ask them a question many years later, they won't be able to participate answer; if you invent a sarcastic reply, it's like kicking a defenseless person - again, they can't answer. So, it's best to speak to the living - that is, start a new thread, possibly with a link to the old one.