$0.02:
In
Mexico (and many other countries), there is no prescription required for antibiotics. As a kid, we always had a stock of amox and keflax hanging around. It really doesn't take a medically trained professional to diagnose a stinky sore that's oozing goo and say "hey, that's infected".
I'm sure there are a lot of people who take the wrong pills when they self diagnose, but even with
health insurance, I've managed to skip the doc for a variety of skin, sinus, and other infections that required antibiotics. And, so does the vast majority of the world.
I'm fully aknowleding that there are a lot of problems with untrained use of antibiotics, but if you have a real infection, and you're in a country where you can buy an antiobiotic that you know you're not allergic to, you're going to look really silly when they need to chop your arm off because the staff infection got out of control.