But doesn’t include California.

Yes it fking does. The Bay Area and coastal Northern California is practically identical to Portland climate wise. Check a map of the PNW, nor cal is usually included.

Crescent City is the only town in California that I would consider part of the Pacific Northwest with a Walmart. [1]

Which is to say the technical definition doesn’t conform with most people’s experience because relatively few people know of Crescent City.

[1] Eurika is in Humboldt County and Humboldt County is not the PNW, it is Humboldt County.

I never understood why people say SF is NorCal. It's only halfway up the coast. I know of Crescent City because I drove up 101 once, and we stopped there. We were amazed at the size of the redwoods around there. Each time we drove around a switchback our headlights illuminated another one which we would collectively gasp at. Later on we got a traffic ticket on our way to Grants Pass. It was worth it though, as Crater Lake was similarly impressive.

It's because there is no major city north of the larger SF area. It's weird though

Also because the micro-climate of the penninsula, SF proper, and a decent bit around the bay is almost identical to the rest of the PNW. The culture is also nearly identical.

I went to a bar in SF that had some graffiti all over it. One of the graffiti said "Itching to get out of Portland". I asked inside about it, and they said it's because at the time Portland had a bedbug infestation.

No it fucking does not. No one refers to California as the PNW they refer to California as California.