Any cultural grouping that claims Humboldt and Tahoe aren't more closely related to each other than either are to the central valley is quite wrong. California pretty cleanly splits into 4 cultural regions: SoCal, The Bay, The Central Valley, and the Mountain Folk.

If you posterize enough to get to a map this course, then you'd have "The Left Coast" running down the Sierras, with parts of Klamath and Cascade Ranges (notably excepting the Shasta corner, which is more closely related to the Klan country side of Oregon). This can be somewhat justified, if one argues that the difference between the cultural ideas of the Bay Area are just urban versions of those that occupy the mountains (oddly harmonious mix of hippies and libertarians vs. the Bay's coexistence of corporate libertarians and progressives).