They broke the law. This isn't that hard to understand. If you don't like the law then either work to change it, create substitute works, or break the law in a way that doesn't involve dragging down the archive with you.
Should they have waited to start this archive, which is important enough for you to worry about its future existence, until the law on the right to make copies of websites was settled law? Bearing in mind that there are ongoing lawsuits and discussion on this topic right now, over fifty years since the emergence of the digital networks that rely on making copies to disseminate information.
Do you think that there was an open-and-shut case for an online archive in 1996?
When you watch anything on Netflix, the movie is copied a few dozens of times at least, and even you make a few copies during watching it, but I don’t think that it’s legal to make a copy, I’m quite sure that it’s stated in their ToS. So the whole internet infrastructure, and computer manufacturer, and every user should be sued with this logic.