There's no concept of deleting an article because it isn't being "maintained" -- the article existing and being gradually modified over time is its "maintenance

There's no concept of deleting an article because it isn't being "maintained" -- the article existing and being gradually modified over time is its "maintenance". If it was wrong when it was originally posted, then that should ideally have been worked out and corrected early on. If not, then it was a case of new information still being wrong, which is always a risk with a mass collaboration project like Wikipedia, regardless of how old each particular article is. If the information is merely outdated, that's immediately discernible by looking at the age of the most recent edit. In either case, the way a wiki works is to gradually accumulate improvements in accuracy, detail, and and thoroughness over time. Deleting content prevents this from happening.