I'm not here to defend selling bushmeat or the trade of wildlife for "medicine", but wet markets are simply markets where farmers can set up stalls and sell directly to consumers, including livestock and meat. Yes, it doesn't have the same sanitation code as supermarkets, but these wet markets are actually just what regular markets looked like 100 years ago. There's nothing nefarious going on there that breeds pandemic, except for the ones where they trade bushmeat, but these are exceptions; and the problem is the bushmeat, not the wet market.
This author is painting a picture of wet market like it's some kind of seedy underground butcher shop, but the reality is that this is how places like New York or London were selling groceries and food just a hundred years ago. It's just a regular market before the age of super markets.