Are you retarded? No, it is never the point to hurt your opponent, and certainly not to that degree. Supplexes are used nearly exclusively in professional wrestling--staged entertainment--because they're flashy and look baller. Even if some tard tried to use it in an actual sports wrestling match, the point of those is to pin your opponent, not fuck up their neck and leave them paralyzed. Even "no holds barred" matches like MMA faggotry tend to look down on competitors that aim to permanently maim their opponent.
All that's left is actual fighting to defend yourself, in which case, yes, you're right: the point is to hurt the other guy. However, if you think a supplex is in any way an efficient or effective mode of self defense, then I am forced to conclude you are not only retarded but also fat, 14 years olds, and currently sporting a TAPOUT t-shirt, because only underage fuckups think WWE moves like supplexes are "real fighting" and not intense, physically demanding choreography.