So, living in places like that and paying that much is definitely not normal.
For 1900 $/mo, you can get a bedroom in a really nice 2 or 3BR place in the desirable neighborhoods or a studio/1BR in the undesirable neighborhoods (sunset/richmond). I don't understand why the people in that article are living like that (Poor credit? Desperation to find a place fast? Ignorance of the existence of Craigslist?), but they're very, very far from being representative of SF real estate.