I'm not trying to be snarky -- I rarely see cars stop for stop signs; I normally see cyclists slow down at stop signs, and I rarely see any cyclists completely blow through them. (I also rarely see cars completely blow through stop signs.)
My common-sense understanding of the difference is that a cyclist can more readily hear what is happening near an intersection, has fewer visual obstacles to see what is near an intersection, and is often already moving slower than a car. That makes me feel that a cyclist rolling through a stop sign is far less dangerous than a car doing the same.
My experience has been in SF/Oakland/Berkeley.
Anyway, the reason I added that link in the earlier comment was to illustrate my frustration with the "all cyclists break laws all the time, they need to be safer like cars" fable -- the article links to a study that found that by 1996, only 1% of cars stopped at the stop sign being observed. Of course there are cyclists who break laws, but there are far more drivers who break laws, and they are the more dangerous offenders.