Here's why: The plant has operated for more than 3 decades without killing anyone, ZERO people. During its operation the State of California lost tens of thousands of lives to air pollution, if not hundreds of thousands. Tens of thousands more died in automobile accidents.
This obviates the mentality of anti-nukes perfectly. They don't give a shit about was IS happening but elevate their paranoid fantasies over human life, based on their imagination of events that they have convinced themselves are inevitable, even though the evidence shows they are hardly, not even remotely, so.
Like their enthusiasm for the failed and expensive, and frankly environmentally questionable wind industry, they elevate "could" over "is." The wind industry is not producing significant energy, and yet, almost half a century of experience with it, they keep claiming it could do everything.
It hasn't; it isn't; it won't.
The example of Fukushima shows this in spades as well. In that earthquake 20,000 people died from seawater, while deaths from radiation, if in fact there were any, were vanishingly small.
Yet our anti-nuke community is doing everything in its power to assure rising seas and thus even more seawater deaths,
It is a crime against all future generations to shut Diablo Canyon.
The logic of anti-nukes is bizarre. Compared to to other technology related accidents, for example planes, trains and automobiles, half a century of commercial nuclear power is remarkable in how little loss of life it's involved.
I'll consider taking the deadly rhetoric of anti-nukes with slightly less contempt when I find one who's anti-car. So far no luck.