Why is there not even ONE ''left-wing'' radio station here in supposedly ''left-wing'' San Francisco ?

simple....

conservatives, by nature, are "buyers"....they want something that resonates with their core values, which are more-or-less consistent, thus making programming and selling advertising rather simple...

liberals, by nature, a "sellers"...they want to tell you what resonates with them and have you affirm it, but their values tend to shift and flow with the times... in our instant-media culture, this could literally mean day-to-day... 

this makes it extremely difficult to determine programming and near impossible to sell advertising...without which radio stations fail... this is why most "liberal" radio stations in major markets are publicly funded... and why national networks like the former "Air America" eventually fail...

wasn't it in "liberal" San Francisco where the Whole Foods was vandalized when it was discovered that it's locations in riot-torn cities were giving free snacks and water to National Guard service members?

wasn't San Francisco where Gavin Newsom made his name pandering to the same-sex marriage crowd that's now calling for his recall for not doing enough?

more often than not, "liberal radio" fails because they eventually run out of energy chasing constantly-moving targets...

Radio's for music.

Use TV to get propagandized.

There is left-wing propaganda in every direction you look. Why would you also want it on the radio?

KQED is very left-wing. KGO definitely skews a bit left.

I know.  I live here and have listened to them both.

There are also 3 or 4 lower power college radio stations in Berkeley, San Jose, etc.....all left-wing as well.

Talk radio is kind of an older media and seems to be more of a right wing interest these days. Left wing people may more often just prefer other sources and doesn't make radio worth the cost.

Ballet harvesting is legal in ur state buddy. COMPANIES are allowed to collect ballots on the behalf of the government. Doesnt that seem suspicious. California is one of the only states allowing this. Even though this is true trump has more than 40% of the californian vote. Imagine if companies were not allowed to hold ballots which are not checked for ID by the way. The voting laws in california are a joke. 

Talk is for people who want to lie and cannot or will never "do". Why waste any time on talk when you can be doing while listening to music.

Mainstream news (tv) takes up that slack.  No need for radio.  

Only the 70+ crowd listens to radio