I've never understood the problem with thread necromancy, personally. I just like to observe local norms when it's easy to do so, and they're applied to everyone (*cough* consecutive posts is spamming *cough*).[Out of curiosity, why do you take that position? On some boards, they want the old thread ressurected as it will have all the old conversations, and possibly prevent retreading, or enable the opportunity to readdress an old thought from a different angle. Yet, on other boards, resurrecting an old thread is practically a Cardinal Sin. Why the difference in opinion?
Well, this is a large board with a big turnover of threads and posters. If you resurrect a quite old thread (let's say a year old) you have pages of posts from people who aren't necessarily around for the resurrected debate or who have already forgotten what they posted in the thread so you might be arguing with phantom posters and opinions. Recently, there was an old thread resurrected here and the arrow symbol on the thread showed me that I had apparently particpated in it at some point but I couldn't remember what I had written.
I guess that's why it's not a hard rule and there's some leeway in handling this. It isn't an actionable thing, either, unless you do it to annoy people.
I guess that makes sense. I still think it makes more sense not to reinvent the wheel - especially given there's an entire subspecies of forum poster that delights in saying "use search, newb," or linking to previous threads on the topic in lieu of an answer - but whatever.