Not all wet markets sell weird animals to eat. But those that do should be closed. If they are just selling vegetables and Beef/Pork/Chicken like in HK, Taiwan or Singapore they are probably fine (Though they are still a bit dirty.
A bit dirty??? Ever been to a wet market in Taiwan? Blood, guts, poop everywhere. Never saw anyone putting ice on meat displayed for sale. Wanta buy some chicken guts? Lady holds an intestine up and cuts off what you want. Clean the poop out later.
The fish wet market I was in was even worse. Dead fish laying everywhere. Want a piece of fish? Butcher tosses a fish on the table and cuts it up in front of you scraping the guts off the table as he works.