It exists for people who can't or don't do their homework and find a reputable surgeon who operates in a good hospital with a full team and all the necessary medical equipment for any kind of emergency, while finding a place to stay during recovery. I'm sure that many medical tourism companies will also throw in a city tour and a free tango show too.
An Argentine friend of mine was operated on at a well-known medical tourist clinic in Buenos Aires. The doctor didn't order an EKG before the surgery, and he didn't even actually operate on her but let his assistant do it. The anesthesiologost allowed her to scream in pain so much that they stopped the operation half way through. The doctor in question told her he most certainly was in the OR with her and she said he wasn't. She was wide awake enough to get off the operating table and walk home. There are other similar cases including fatal ones involved with surgery tourism. A good doctor doesn't have to associate himself or herself with a medical tourist website in order to get patients.
That is a horrifying experience.
I did know the owner and worked for him shortly when I first moved here many years back. He worked with good surgeons and hospitals as far as I saw. But obviously you should do your research regardless.