Isn't it quite difficult to know what is better, even if the question weren't subjective?
It is very hard to conduct randomized controlled and double blinded trials on forms of government. I don't think people can even agree on how to measure how good a government is.
No one cares about these examples because no on is arguing that China's system is better than Taiwan's or that North Korea (!) is better than South Korea.
What we are actually discussing is whether, for example, Denmark is better than France or the U.S.
