The problem with that article is that it ignores nationalist sentiment on the Mainland, and misunderstands the complexity of popular sentiment on Taiwan. Also it attempts to analyze a situation by applying rational rules, which causes problems because 1) other people may not accept those rules and 2) without referring to fundamental issues of “will” and “power” any rules you come up with are disconnected from reality.
With regard to “will” and “power,” the basic reality is that public sentiment on the PRC is such that people are willing to fight for and die to keep Taiwan from being independent, whereas the number of people on Taiwan that will fight for and die for independence is relatively small. The other basic reality is that while the major powers of the world will fight in case of an unprovoked invasion by the PRC, no one is willing to fight and die to defend a unilateral declaration of independence by Taiwan.
The reason that popular sovereignty trumps historical claims is that claims that people are willing to die for trump claims that people are not willing to die for, and any discussion on Taiwan has to take into account the fact that there are huge emotions on this issue among the population of the PRC, and any PRC would be forced to take strong, possibly suicidal, action to prevent “de jure independence”.
The other thing that is missing is that while no one on Taiwan wants to be ruled by Beijing, there is a large fraction of the electorate that is against “de jure independence” or “one China, one Taiwan” for emotional reasons, and pushing Taiwan to one of those options rather than keeping the situation ambiguous is extremely destablizing for Taiwan democracy.
Finally, analogies with other situations are useless if you don’t take into account “will” and “power”. What matters is what people are willing to fight for and what people are willing to die for. The willingness to fight and die for a cause is fundamentally irrational, and therefore trying to come up with a rational rule that explains why one situation is analogous with the next is rather pointless. Also trying to come up with a political sentiment that doesn’t take into account “irrationality” is also pointless.
This makes Taiwan different from a lot of other situations, and it also makes this different from other PRC disputes. Askai Chin, the Spratlies, and Senaku/Diaoyutai simply don’t arouse the passions that Taiwan does, and this limits and constrains the situation. Also once you recognize that the root causes of political conflict are because of inherent and *necessary* human irrationality, you can come up with solutions that address these issues. No one really cares if Beijing effectively rules Taiwan, what matters are names, flags, and colors, and you can deal with those relatively easily.