This is one of the few issues on NS that has existed since at least 2002, and I think what it comes down to is that the search function has never been revamped (with the brief exception of the google search). If I want to make a thread about Tom Wallisch on Scott, and as a good NSer I do a quick search for Tom Wallisch Scott or TWall Scott, I get no results. If I do a search for Tom Wallisch, or TWall, I get the 50 most recent threads, none of which are relevant. A search for Scott doesn't turn anything relevant up either, so I now know that nobody has ever made a thread about Tom Wallisch signing with Scott.
It's not that people don't try to prevent reposting (considering how many threads start with "Sorry if this is a repost, I searchbarred"). But for "part-time" or new NSers who don't read every single thread on NS all the time, the searchbar is fairly useless tool for them to prevent their reposts. It's also pretty useless for NSers who are trying to provide links in reposted threads if the original thread can't be found. Reposts are going to always exist on any large internet forum, but if NS had even a few more search options (search without exact phrasing, search posts, more than 50 results, etc), we would have many fewer reposts.
