I for one am opposed to showing the thread start date. The more clutter there is in the thread listings, the harder the program is to use.
I'm not even sure the moderators have access to the coding tools to rewrite the user interface. They're not site developers, just trusted users with greater user privileges to edit, delete, or lock threads and posts.
Thread necromancy happens from time to time. I've accidentally contributed to the problem more than once myself. At least with thread necromancy, as long as you're not looking for a response from a Forums user who isn't around anymore, there's no harm done. If an old topic is still pertinent enough for new people to post to the thread, resurrecting the old thread can be just as valid as starting a new thread on the same topic.
I thought getting old would take longer!