For example, AFAICT few people say that China doesn't take enforcement of trademark protections seriously. The procedures for redress and enforcement exist and applied fairly. But navigating the administrative state can be confusing and cause people to trip over the technicalities. Some of the stories I've read from the blog above detail situations where Chinese partners or workers used the legal system against foreigners in very surprising but arguably fair manners. Much like the U.S., if you want to protect your rights you really need to make sure to employ vigilant lawyers who can foresee potential problems.
The U.S. is large enough that there's been little pressure to address issues of regulatory and procedural uniformity relative to the rest of the world (e.g. civil law countries). China is similar in that regard. What's different is that China's systems are almost wholly unique and far more complex, whereas the legal systems for almost all Westernized nations, including Japan, have a pedigree that can be traced back to Western Europe, if not ancient Rome. China has been adopting American-style legal rules and norms for commercial law, including common law rules about case precedent. That helps further the rule of law and, more importantly, provides processes more familiar to foreigners, but it also adds yet another dimension of complexity.
To use communism as an example, again, consider that American tripartite system of government--legislative, administrative, judicial--can create substantial complexity relative to a small, autocratic state.[1] In China the Communist Party is another pillar of governance in addition to those other three, multiplying complexity. And China has a federal system much like that in America. So just because things are confusing and seemingly haphazard doesn't mean that they actually are. I mean, China has had a robust and effective administrative state for millennia. IMO much of the perception of China as chaotic and full of cheaters is self-serving. And to the extent it's correct, I think it says at least as much about the limitations the central government faces than about their lack of desire or will to do anything about it. If we don't appreciate that than we're simply going to frustrate ourselves with demands and expectations that are misinformed and unreasonable.
[1] For example, in the U.S. using a judicial judgment to induce a government agency to do or abstain from something can be challenging and expensive. We maintain especially rigid separation between the judiciary and executive for good reasons--reasons directly related to our conception and experience of rule of law--but that does not necessarily translate into efficiency or even consistency.
Xi has tried very hard to stamp out any dissent via his "anti-corruption drive", but it still exists. There are various factions vying for power behind the scenes, some ally themselves with Xi, and some do not and are simply biding their time & waiting for Xi to screw up and "lose face".
You wouldn't be the first person with real experience working in China making that point. From everything I've read the IP issue is way overblown. There are some high-profile cases but in general it seems to be used as a convenient cudgel for other purposes.
AFAICT the real issue working in China is that it's a communist country, heavily bureaucratic with byzantine and entirely unfamiliar legal systems and business networks that almost everybody else, including to a lesser degree other East Asian countries, find very challenging to navigate. Even corruption works differently there. Because it's a communist country power and influence flow in unexpected ways even when everything is above board.
The upshot is that even when criticisms about China are reasonable, they're kinda beside the point because they're not the principle reason companies find it difficult to operate there. Even when the Chinese government wholly cooperates with a reform measure--passes and earnestly applies a law--things invariably go sideways for outsiders.