Airports can replace the TSA with private contracts. SFO farmed security out to a company called Covenant. They still have to follow TSA policies and aren't necessarily an improvement from a passenger standpoint. I.e., you're still getting yelled at by otherwise-unemployable nitwits on a power trip.
I've actually found the SFO private contractors to be fantastic. I once left my laptop at the security scanner, and they shipped it to me next day (at my expense) where I urgently needed my laptop the following day--it was boxed and packaged nicely and sent to FedEx for me for free. I just had to send them a PDF label. They simply verified serial number. They had a great lost and found tracking system and called me "customer."
The other time I brought some Chinese takeout that had a lot of liquid in it. The scanner said for future reference try to order drier dishes (I brought a papaya with soup embedded in the cavity), but she was going to look the other way and winked at me and told me to enjoy dinner.
Never had to wait long either (but I have TSA Precheck) and don't recall being barked at... I did have to wait quite a bit in the official TSA Precheck line in EWR though (those were DHS employees) and dealt with a slew of surly employees...
If we are going to have to have TSA, I'd rather have the private contractors run it than the TSA. No Stockholm syndrome; just thought they offered a better experience for the same thing than the TSA.
Oh really? That's depressing. I fly out of SFO all the time, and it's the only airport where I've had to wait in security for more than about 15 minutes.