There is simply too much nationalism and national pride locked up with the whole South China Sea and Taiwan that no amount of logic and truth can change how it is perceived in China.
The South China Sea dispute has nothing to facts like these, and all about geopolitics and power within China. Like with the Austria pre-ww2, if the Chinese were to invade and conquer Taiwan and control the entire SCS, they'll magically find other "distractions" and "conflicts" to distract people away from their own misrule and corruption.
With Putin's Russia and the CCP, there must always be enemies (both internal and external). If they don't exist, you create one (think FalunGong)