I dont LOVE buying used clothes, but i have bought a few used items that are in pristine condition.
Like others have said, when u go to buy a shirt from a store, there are countless amounts of people who've tried it on before you buying it! (dirty people, sweatty people, people with skin problems, people blowing their nose into a sleeve-and dries up etc....)
Plus, clothing is clothing, its not like you'll wear it forever.
Some people, like me, tend to buy items on impulse only knowing that after wearing it 3-5 times that i'll never wear it again.
This is why mankind invented things like soap and washing machines capable of washing with hot water