Wearethemods - thanks for taking the time and trouble to make the post above - it's something we as a team (and probably other members too) do keep an eye on, and sometimes we do try to bring them onto the list of current threads by posting a similar comment.
There is a concern, however, about trying to make contact with the originator (o p) of an old post, where he/she has not posted (or visited) the forum either since them or for some considerable time - there may be a reason for their absence which we are not aware of, and which needs to be respected.
Highlighting old unanswered threads is to be encouraged, in the hope that the o p may see the thread reopened and decide to respond in some way, but it is felt that that direct contact should be discouraged, unless it is known that the o p is still an active forum member.
As moderators, we have access to such information, so if anyone wishes to contact a member and wishes to check with us whether they are still active on the forum, then do not hesitate to ask.