Same here! Yes, I used it as the well-known site that supported unencrypted http and no HSTS. Yes, I was one of those guys using the site "as a service" rather than simply documentation. Admittedly, it was perhaps interchangeable with other sites, but since it reliably worked for that purpose, I couldn't be arsed to find other ones.

Isn't there a dedicated site called nohttps or something? NeverSSL? I just tried http NeverSSL, and it redirected me to an https page with a random hostname and an Amazon SSL certificate!

Does example.com still function this way, with http and no HSTS? I noticed that my Chrome browser was immediately redirected in the customary way.

http://neverssl.com/online/ seems to work for me?

Are you perhaps on an untrusted network which is spoofing that url to make it redirect somewhere else?