Well, the Google Cache[1] shows it as last snap-shotted at Apr 2, 2022 05:48:34 GMT, and the captured page doesn't have any announcement about the site shutting down or anything. If I had to guess, I'd say it went down because of a server crash or some network issue. The open question, if I'm correct, is "will it be back up, and if so, when?" Not sure about that. I hope it is coming back though, as it's a site I also enjoyed perusing from time to time.

[1]: http://webcache.googleusercontent.com/search?q=cache:XjPUGeG...