Lincoln Island (Dong Dao) is the second biggest island in Paracel - 160 ha. It seems that China hasn't developed the island at all, why is that?
It's very close to woody island (San sha), so little value in investing all that money and resources to build another major base pretty much next door to one you already have.
The Paracels are also much closer to China, and China enjoys total, unchallenged control of those islands.
All that means that China does not need to physically station men on every island and feature in the group.
Another country's forces even approaching the islands would be spotted well before they got there, and thanks to its base on San sha and the closeness to bases on Hainan, Chinese forces could quickly be dispatched to challenge and drive off any land grab attempts by others.
One of, if not the primary reason land grabs was allowed to go on for so long in the Separately was because it is so far away from China, and the lack of a major Chinese base in the area until recently.
Before, China was having a hard time even monitoring what was happening in the area.
China didn't know about the land grabs by the other nationals until a fair while after it had happened, meaning foreign forces were already dug in by the time China could respond. Thus any Chinese response and attempt to dislodge the squatters would have almost certainly required the liberal application of overwhelming deadly firepower.
In its naivety, China thought that wasn't a very mature and responsible way of dealing with the situation, so decided to try diplomacy. Now it is effectively having that earlier maturity, patience and self restraint thrown in its face and being punished for it.
Few would have batted an eyelid had the nascent PLAN turned all the outposts land grabbers established into charred holes on the beach a few decades ago. The forcefulness of the response would have given others pause, and set a precedent for dealing with future squatters, and there would be no problems in the SCS today.
The overwhelming lesson that the west in general, and America in particular, has been hamming home on China has been - don't be nice, be a badass.
And you know what? China has decided to start taking the hint.