It's almost always cloudy in Seattle, but when it is cloudy in Seattle, it is at most a coin toss whether it will rain, and of the approximately half of the cloudy days when it rains, most of those days, in most of the area, you won't actually notice the rain because it will dry faster than it hits.
San Diego has far fewer partly cloudy days, and the number of days in San Diego that could be legit described as "grey days" are _really_ rare. So I'm just not sure what to make of all this, other than that it's a terrible comparison based on a wild misunderstanding of Seattle as a place where it rains all the time. Which is most definitely does not.
OTOH, notice that this is an _opinion_ piece, not actually a real news article at all. *sigh*
ETA: Here is a MUCH better opinion piece on an entirely other topic. Dancing Deer makes great cookies, and Trish Karter tells an amazing, inspiring and wrenching story that everyone should think about before they get all I Can Tell Other People What They Should Do on such a difficult topic: