It would certainly be a Big Deal if we lived in a country controlled by the Vast White Racist Conspiracy. Actually, San Francisco is especially notable for its deeply entrenched racism. The KKK has a huge office on Market Street, right next to Twitter - you can't miss it.
Are you a visible minority? I can tell you straight up right now that racism in San Francisco is a Big Deal, though the SF-is-paradise brigade would never accept that.
Note that the below applies to just about any place with any significantly racially diverse population, it is far from exclusive to SF - though many SF residents seem to pretend they are an island of racial equality.
There are two broad types of racism: the blatant, violent, and openly hateful racism that you see from the likes of the KKK. The other is the subtle, subconscious, but far more pervasive and damaging racism that us minorities have to deal with every day. The more liberal members of our society openly mock the former, while their hearts and minds are filled with the latter.
On a bad day I wish we could trade in some of the latter racism for the former. At least openly hateful racists are easy to identify and easy to dismiss simply because of how ridiculously venomous they are.
Indeed, it is the more insidious, less obvious racism that affects our daily lives. It is the broad racial stereotypes and preconceived notions that prevent us from achieving what we want. It is the subtle segregation that keeps us from being full, first-class participants in our communities. It is the exhausting need to topple every awful stereotype on a long list before someone is capable of perceiving you as a unique person.
It's the woman who suddenly clutches her purse more tightly as you pass by on the bus. It's the man who mistakes you for the kitchen staff even though you're dressed for a nice dinner. It's the coworker who keeps giving you the math-heavy jobs because, hey, you're supposed to be good at that right? It's the stranger on the street who feels the need to dumb down his English to kindergarten levels because he's assumed you can't speak it. It's the girl you're on a date with who seems more enamored with your race's stereotypes than you. It's shocked looks when you assert yourself in a meeting because everyone expected Your People to be mild and soft spoken. It's the fact that, despite being one of the largest racial minorities in the country, and the region, your representation in upper management is a pitiful fraction of where one might expect it to be.
None of it particularly hateful, none of it particularly vile, but also universally present, and in aggregate far more hurtful than a handful of ignorant people waving placards. And the worst part is that nobody but us notice it.
I won't pretend I have it the worst. I'm East Asian. Far, far worse experiences abound in liberal-utopia San Francisco if you're Hispanic, Black, or South Asian.
Just because you live in a place where crosses aren't burning on lawns, where whites and blacks don't have separate water fountains, do not presume you're even remotely close to being free of racism.
I liked your post, but this point I don't think I can relate to.
Do you include cultural attributes in the stereotypes definition? For example, would it be racial to assume that your relatives are close to you because it's common in (East) Asia?
I think potatolicious is referring to things like "is it true you black guys are well-endowed" or "I bet you Asian guys are really good a math and karate," etc.
These preconceived notions can interfere with relationships and put pressure on people to act in certain ways, which might not be in keeping with who they actually are.
That being said, my biggest exposure to racism has been from my own extended family towards people of just about every other race. Even my mother who's relatively moderate advised me to 'never trust the white man in the workplace' as they would always promote each other over a "Paki". My family has just about everything from your uncle with crackpot zionist conspiracy theories all the way up to real-life war criminals who raped their way across Bangladesh in the 70s[2].
The reason I bring this up is because it's the same hateful, blatant racism, but it happens behind closed doors and even receives protection from the government. In the eyes of my family, my Japanese wife is a kafir, or 'infidel' and in my family at least sub-human unless she converts to Islam.
I'm obviously an extreme case (I sincerely hope I am!), but anecdotally I don't think that my family is of the only minority that has this level of culturally ingrained racism. I have friends of East Asian descent who report similar sorts of stories from their own families 'back home'. My in-laws (who have literally never left Japan) are obviously racist, but not in any overtly malicious or harmful way, so I think I can forgive them the occasional awkward question about 'my people'.
Given my experiences it's very difficult to get all that worked up when our product manager mixes me up with the other brown guy in the office or when someone casually assumes that I had an arranged marriage. The perpetrators in this case feel guilty about their mistakes and apologize. That my own family doesn't have this level of cultural awareness is a source of immense personal anguish to me.
[1] I actually feel quite secure because I get searched as often as I do. In my case at least I believe the racial profiling is accurate. As a child I went to the mosques where the extremists preached and there's only a very fine thread of causality that lead to me being a Dawkins-quoting Atheist instead of a fundamentalist muslim.
EDIT: That being said, other than your claim that only minorities notice subtle racism, I agree with everything else in your post. Well spoken and laid out.
It appears you have a significant axe to grind. From where it came we can only speculate. In the end you look like such a radical apologist for all things racist and homophobic to be at the same, just polar opposite, end of the spectrum as you think the author of the original post to be.
Do you think it's implausible that the pendant woman got fired? Would you say, that kind of thing can't happen in America?