The social justice warriors aren't "running around". They're flagellating each other in mostly self-selecting circles. People who complain about social justice warriors as though they were commonplace are doing the same.
Most of the less extreme views on this lead to good places - the are deficits in hiring certain classes of people that are worth fixing for the sake of both economics and decency. There are some pretty rampantly abusive environments born when you give a 20something millions of dollars and a building.
I met probably a dozen people (coworkers, acquaintances, etc) in my years there that took this to an unhealthy, draconian extreme. But they're the overwhelming minority. And some of them got rightfully fired for their antics.
If you can avoid being lazily bigoted and sexually offensive, you'll do just fine. The standards of conduct are very reasonable.
On the other hand, if you're OK with being respectful to people even if you disagree with their very existence, you're pretty much good to go in the Bay Area.
As an example of this in action, I have a gay friend who eventually moved to New York City with his husband. He works in a big bank in a mid-level job, you'd recognize the name. His manager constantly refers to my friend's husband as his "partner". My friend thought he was going out on a limb when he corrected his manager with "Actually, he's my husband." It's fine to be forgetful; it's not fine to be disrespectful. So far nothing bad has happened, but who knows how it will turn out.
Because it's not about you. The Golden Rule is not "call people by the name you are ok with if you were them", it's "call people by the name they want to be called by". If you like, I can pull out my Miss Manners book and quote that rule to you, from the 1950s.
And in the specific case you mention, I'll say as a gay marriage advocate, that someone who doesn't believe in gay marriage should not be forced to use terms they believe apply only to heterosexual marriages. IMO both of those people are entitled to their views and preferences and both need to agree to disagree. Without being disagreeable.
The problem is that people read way too much into what other people say. It sounds like you hear "partner? this person is clearly insensitive to the history of discrimination again LGBT people."
Instead try "I don't like the word partner, but it is a pretty standard term for not only the unmarried, but also married people. This guy probably doesn't understand it bothers me, but I'll give him the benefit that he meant no harm."
And so is my gay friend in NYC. It's just that he's scared that his boss is actually a passive-aggressive homophobe and he's going to get fired for politely insisting on "husband".
He's just scared.
Keep in mind that he spent the first decade of his career working in places where he could be legally fired for being gay.
And there are lots of parts of the US where he could still be legally fired for being gay.
There are plenty of people in the bay area that have more conservative values, if for no other reason than that tons of people move here. Nothing particularly bad seems to happen.
Here are some examples I found searching the interwebs: http://www.breitbart.com/tech/2017/01/11/sjws-tech-conferenc... I remember the incident about Douglas Crockford as a big WTF that confused the hell out of people.