Even scanner enthusiasts should know some frequencies just aren't published. Think what you want about open access, etc. It's about Everyone Going Home. These would be Special Ops, Surveillance frequencies, etc. Not the little know security or other channel used from time-to-time. They're game.
Then as ecps92 said, people want to get all the info from somewhere w/out looking or putting any effort in.
Then finally, you can submit info to RR for Malls, and lesser known frequencies here all ya want. if you're lucky they might be published. I had a bunch I submitted a couple months ago or more and they just made it in. Those replaced previous submissions that were never published.