Is that there are far more cats than there are people who want them. Many millions more, and if your cat is not a kitten the odds are against her ever finding another home. The number of healthy cats euthanized in US shelters each year due to overcrowding is staggering.No kill shelters vary in practice. The SFSPCA is a closed door shelter. The SFACC is the city's open door shelter, and the SPCA chooses which animals they will take from there based on the room they have and the perceived adoptablility of the animal. Other "no kill" shelters take from the public, but none are "open door" and they have long waiting lists. All shelters (including "no kill" shelters) will put an animal down if they are unhealty (physically or behaviorally) if they believe that too much money or effort would be needed to rehabilitate or manage its condition.
If you are still living in SF and your cat is healthy, speutered, and has a level 1 or 2 personality (doesn't ever scratch or bite, affectionate, gets along with other cats) I'd say it has a pretty good chance of making it if you take it to the Animal Care and Control. Ideally it would get adopted fast or picked up by the SFSPCA, which has the best shelter a cat could want for. We joke with our cat when he's bad that we'll drop him off at a shelter in Modesto or something. We adopted him from the SFSPCA and he had his own room 3 times the size of our bathroom with a huge cat tree, big windows and a TV that played bird videos on it. The SFSPCA will also take back any cat they adopted out, so if you got the cat from them, they'll let you return it, even if you live in another city now.
There's another bay area cat rescue with a huge facility that's no kill (not 9 lives, though they're good too) where they'll take cats off a long waiting list OR take your cat if you pay them like $1,000 or something. If you can't get her into one of those places, I'd suggest you make every possible attempt to keep your kitty. Sadly there just aren't enough homes to go around- not even if you include bad ones.
ƒK