People sometimes use major airport codes as shorthand for a city or the metropolitan region the airport serves.

People who live in San Francisco don't use SFO to refer to the city.

The airport is actually a couple of cities away (there are a lot of cities in the Bay Area).

People who use airport codes to refer to cities don't care.

I would hope not, considering many major cities are serviced by multiple major airports.

NYC - JFK LGA EGW

PARIS - CDG ORY

London - LGW LHR

Tokyo - NRT HND

SF - SFO SJC

If someone starts refering to a city by the airport code I'd be completely lost because most airports and their codes don't reflect the name of the city they service.

SJC doesn't really serve SF. You can say OAK sorta does, but not really. It's pretty clearly SFO. Also, the BART line to SF is called SFO (used to be called whatever terminating city until they realized that's stupid).

From my experience doing so is a good way of coming across as a douche tech-bro (“yeah, I’m so cool I use code names”). Particularly when the comprehensible way would be to write SF rather than SFO.

I should get a Patagonia that says "SFO" on it. I already have the EECS Supreme shirt.

We have the best pizza in ORD

We have a datacenter there, so I'd totally know exactly what city you meant by that. I wouldn't say we always call Chicago ORD, but it definitely happens.

Indeed ORD-style pizza is the best.

Back to that same old place, sweet home ORD.

I'd say the worst

It is not pizza, so it cannot be best or worst pizza.

On that we agree, but it's still bad, whatever you call it

And anyplace without a major airport is "flyover country" often to the chagrin of people who live there.

SFO is commonly a shorthand for San Francisco, LA for Los Angeles, SD for San Diego.

SF, not SFO

Username checks out.

Nobody refers to San Diego as SAN, even though LAX is used for LA, the airport, and the train station?

Just be glad you don't live in Cumaná I guess.

SFO, LA, SD. One of those is not like the rest.

no, SFO is an airport