I have seen many, many knife injuries in the field, and have seized a pile of knives used to cut or stab people.
Some are crappy folders, some are box cutters, but the VAST majority are cheap steak knives, or no-name kitchen knives with those really tight serrations (Wiltshire maybe?)
I can't remember ever seeing one that was broken from the knife fight/stabbing, and all are thinner and more brittle that a Frosts of Sweden blade.
I even worked on a murder in my first year as an LEO that was committed with a Frosts Clipper. 11 wounds, no real damage to the knife.
This is not to tout the ability of the knife, or to minimize these crimes in any way.
The point is any knife can easily stop or kill a human without breaking. Moras and steak knives are thinner, lighter and faster, than a thicker, "camp" or "combat" knife and in my opinion more lethal because of it. It is very easy to penetrate clothing, skin, the rib cage, etc with these thin tools.
BUT MORE IMORTANTLY...
The idea of planning to use a knife for self defense is dumb. A wooden staff, baton, club, whatever, is much better. A firearm is better still.
Using your head to avoid these encounter is best, and is only vary rarely unsuccessful.
The purpose of a knife is to cut. This includes making/shaping other tools. Why split big wood with your knife?
Why do pull-ups on your knife handle? (save it for the gym, Arnold)
I will bet cash money that a person using a Mora, who understands it's strengths and weaknesses is far less likely to break or lose his knife, or hurt himself, than the guy chopping up the woods with his big bad Busse.
Yes I would trust my life to a Mora.
No, a Mora is never my only knive in the woods. No knife is ever my only knife in the woods.