The parent did not say that Tinder created this, only patented it.

Prior art (ie publicly published examples) invalidates patents, at least in the western world. To that end, if you invent something that you don't intend to patent you should publicly write about it if possible.

You can always review the claims of the Tinder patent. I suspect the application of the "both people have to like" concept is applied differently.

https://patents.google.com/patent/US9733811

The parent literally called it "Tinder’s big innovation"...

Hot or Not had a matching feature? I legitimately never knew this.

Then again I only spent enough time on the site to grok “ok this exists” and never going back.