I think he understands that -- for example, "Confusing one’s own youth with the youth of the world is a common human affliction...", "I have also noticed the friendly crowds jostling my elbows at every surf break and on the shockingly long lines below Yosemite rock climbs. These people have as much fun as I ever did, loving the only version of California available to them.", and the last paragraph. His first impression is dark, but he basically concludes it's not that bad, and that his negative perception versus his nostalgia is part of a cycle that every generation experiences.
He kind of mixes the natural issues (drought) with the human ones (increasing population, re-development). I'm not so sure the two categories will work out equally fine in the end, but I don't live there so I don't really have any skin in the game or knowledge of it.