necroposting is one of the worst things that plagues this website.
How about people not writing a sentence starting with a capital letter? That is even more annoying.
Did you post here just to start a fight?
This is not Reddit or Twitter, for people with ultra-short attention span. This is a proper forum, for sharing knowledge with each other, and on such old threads can be valid.
Some threads are really old, have been active continuously for many years and have hundreds of posts. Sometimes a long thread runs out of new posts, but that does not make it less relevant.
... and
sometimes posting a follow-up post to an old thread that hasn't been updated in a while
is valid IMHO if you have something useful and relevant to add.
Most actual necroposting is done by newbies, and by bots. (which are sometimes hard to tell apart. I don't now what you are)
I think a 120 day time limit for when the warning starts is OK. Maybe it should be shortened to 90 days, but I don't think it needs to be shortened further when peoples projects, companies' product cycles or IC-GB-production-shipping-reception cycles have as long durations as they do have.