Since you are really talking about Bay Area Freeways
then I'd tend to agree, because bay area drivers are terrible. I live near Sacramento, here I would disagree, not because there are fewer idiots, but they tend to be on the streets not so much the freeways and it's a less densely populated area. However, I first started riding on the freeways of Los Angeles, granted it was in the 70s, but I do visit from time to time and the drivers there are better than in the Bay Area, and since the highest risk to a biker comes from someone turning left in front of them, yes, there I'd also disagree, freeway riding for newbies is okay. Biking is NOT for the tentative, nor for those whose situational awareness envelope is very limited. A mature rider (regardless of age) should be able to handle freeways anywhere in the United States (Asia is another matter). There are always scary situations we find ourselves in as bikers, even with the highest skill level we cannot control those around us regardless of whether or not we're on a freeway or a two lane blacktop out in the boonies. BTW I've lived and driven in Sacramento, San Francisco, Oakland, Santa Monica, Los Angeles (echo park area), New Orleans, New Jersey (Scotch Plains area), Cambridge MA (my motorcycling has been limited to California from Redding to San Diego).