To be fair...
Compulsory Purchase in English/Welsh law is the same idea as Eminent Domain (referenced int he article) in US Law.
It still requires a process, and if the relevant governmental entity decides to squash it (as happened here), then it won't go forward.
I think Oregon State did it right WRT this situation; they have a law that not only stipulates that all beaches are publicly owned or have public easments, but any adjacent private property must provide public access to said beaches. If California had a similar law, this case would be open and shut; he's preventing free public access.