Most of that stuff on those ships is containerized. It's just going to get trucked across country, with a fraction actually going into CA. Why not head to another west coast port and unload? If you fit, maybe even come through the canal and unload along the gulf or east coast? You'd pay your crew a few extra days - but you're paying them to sit aboard while they wait. The delta would be the fuel burn, maybe the canal fees and such. But if it gets you unloaded X days sooner, it might be worth the fuel and fees to go somewhere else. I've got to think that for the ships arriving now, with 100 or 200 or so ahead of them, there's no point in waiting, head out.
I don’t know about the suitability of other West Coast ports. Portland, I think, has only one container terminal, and there’s also the question of how big a ship can cross the Columbia Bar and reach Portland. Seattle, no idea.
There are probably contractual issues as well.