I'd be amazed if this were true in SF. I'm an avid cyclist, love biking around the city for fun or to commute, etc. The cause of most near crashes (and crashes) I've witnessed are idiot cyclists thinking it's ok to blow through stop signs or traffic lights, or to wildly cut across two lanes without signalling and expecting the entire universe to notice them and stop for them. When I'm driving, I'm hyper-aware of the stupidity I've seen when I'm biking and try to take that into account when cyclists are around, and I don't blame other motorists for getting pissed or even aggressive. Cyclists have this incredible double-standard...they want to use the road, but they don't want to share it. Sure, everyone who drives a car is an earth-destroying, gas-guzzling, roided out freak who's trying to kill you, but isn't that all the more reason to have some respect for everyone else on the road?
Granted, I've had my fair share of asshole drivers turn right in front of me without signalling or just merge into the bike line for no reason (prompting me to "gently" tap their car window). Hell, I've even had people run red lights and come within a foot of slamming into me, and I've been doored really bad by someone getting out of a taxi, but to be honest I'm as cautious around other cyclists as I am around cars.
Maybe it's just SF and it's the wild west here, but biking at rush hour is just as bad because of other cyclists, not just cars. I think drivers would hate us a lot less if we stopped at a stop sign once in a while and thought about others besides ourselves (same goes for shitty drivers too).