Probably they had been trying to sell it to the state for months/years/decades, and nothing had happened, so they escalated. Here in California in east bay there are thousands of acres of land around Mt. Diablo that are held by a non profit trust because the state/parks department is too lazy to aquire it/don't have funds to manage it. The privately owned/managed land around Mt. Diablo is roughly equal in size to the state park it surrounds.

This kind of thing exists in many places in the USA for many reasons (tax relief, government stupidity or inability or lack of funds, etc).

Sometimes the government is forbidden from buying land but nothing stops an individual or charity.

The East Bay Park district is the largest regional park system in the US, so I'm not sure it's entirely fair to call them "lazy". There's an ongoing fight over whether they should prioritize improving/maintaining/restoring what they already have or acquiring new land.

>Probably they had been trying to sell it to the state for months/years/decades

Third option:

Monks want to put up some minor tourist attraction, put in some parking and hand rails or engage in literally anything, doesn't really matter what since it's all invariably regulated near water. Bureaucrat who doesn't "get it" says no this is a special site if you want to do that you need to do XYZ first or GFY. Monks say we can't afford XZY, that would make this whole thing a nonstarter or defeat the point. Site languishes for a decade or two because while the subsequent bureaucrats may know what's right they can't necessarily ignore what the first guy said without sticking their necks way out. Eventually the monks find someone to help them out who gets the state to take it off their hands. Maybe they monks get a fair deal, maybe they're losing their ass, who knows.

This fact pattern is really common with redevelopment of eyesore unoccupied buildings in prime locations so it wouldn't surprise me to see it going on with some natural site like this.