This article seems to be doing a motte-and-bailey of grossing you out with things that are just “regular meat wholesaler things” (e.g. fresh meat sitting out on ice without refrigeration) and then moralizing about the specific kinds of meats available in certain markets in China.
As far as I can tell, the author really just wants to tell Chinese people to stop eating certain meats (pragmatically, bush meats; but also, less pragmatically, whatever a Westerner would find gauche, like endangered species or things we’d consider pets), but doesn’t want to come out and say what they really mean; and so instead tries to seem like they’re making a point about sanitation. In so doing, they end up arguing against the existence of wholesale meat markets in general, which is clearly silly: meat wholesaling happens all over the world every day and is perfectly sanitary, despite seeming to a layman like it’d be unsanitary. (It is unsanitary in some ways, but in general principle—which can certainly be violated, like any other standard can—it’s always exactly as sanitary as it needs to be for any given use-case. Meats that are cooked get treated with less care; meats that are served raw are treated with more.)
This sort of reminds me of the parable of the new owner who came into a bakery and demanded it be cleaned because everything was greasy. The bakers kindly informed them that the grease was intentionally put on every surface, right after cleaning; and that, in fact, grease is used to clean some surfaces. Some systems function perfectly well in ways that seem disturbing to outsiders. If the bakers have been greasing the bakery for thousands of years, and you’ve never gotten sick from a loaf of bread, then maybe think a moment before telling the bakers to stop greasing the bakery.
Certainly, if you buy a loaf of bread and it turns out to have a bunch of thumbtacks in it, there’s a problem. But not one, I would suspect, endemic to the concept of bakeries.