Groups and lists also existed months before the first G+ announcement. Hard to copy something you don't know about.
FB lists are kind of like G+ groups except they're a PITA to setup and you have to go out of your way to use them when sharing something.
Another thing I hate about FB is the way the entire service is about sharing everything. You have to be really really careful not to overshare anything. In G+ I know exactly what I'm sharing and with whom.
Screw you FB. I hope you die in a fire.