As a former practitioner of Krav Maga, I can confirm that a lot of the techniques are extremely violent. However, it is taught (to civilians) as a self defense system designed to be used as a last resort if you’re assaulted. Furthermore, the reasoning behind the violence used is to shock/stun your attacker enough to let you escape the situation. In fact, whenever we used to practise our instructor always had us pretend to run away after using many of the techniques.
If someone wants to seriously injure and/or potentially kill someone (as opposed to knocking out an opponent or making them tap out) then a lot of the techniques of Krav Maga are applicable, but I sincerely hope that’s not how people approach Krav Maga. I’m unsure if this is common practice worldwide, but our club used to ask for copies of criminal history to make sure that nobody who could potentially exploit the techniques was allowed to practise.