Obviously because they weren't watching their backs.

Kinda hard to do with our spinal columns. I for one, have played quite a bit of TF2, and Spies backstabbing me got pretty annoying, and I'm relatively experienced.
Imagine that happening to a new player. It might detriment their experience quite a bit. It's like the other face of sniping.

But yes, you'll probably manage to kill people from behind without it, being the Ninja Clown that you are.

Yes I will won't I.

I also played TF2. Engineer, Spy, and Scout being my 3 main classes. The spy is all about timing and being where the enemy team doesn't expect you. Once the enemy team is all spy checking each other switch to something else till they get lax again.

Also yes I played Engineer the most. Why? Engineers are always useful Spy's are a niche role that aren't needed as much.

How else are players going to learn to check their six if they don't get punished for not checking their six? Same deal with sniper fear, you learn to not run around in the open because you get dead when you do.

"Fight for any man, but die for none," Sum recte legendi. :spotted owl:

Its an intriguing avatar.

I believe backstabbing could be done if the defending player could counter. Timed-button press sequences might work, along with certain skills or assistance from teammates.

Isn't that a canned animation?

@Wraith: What makes me a good Demoman? Being able to hit invisible spies directly with my GL.

I believe a canned animation is a lengthy, annoying never ending until someone messes up animation that bores anyone who participates.

I was thinking more of a general skill/in-game feature that allows you to block backstabs with a single button-press. If defender lands it and attacker doesn't, defender kills attacker. If attacker lands it and defender doesn't, attacker kills defender. If they both nail it, then they are faced opposite of each other with weapons armed and shoot to kill, like regular gameplay.

Just something I thought would be neat. :shrug:

That is a pretty interesting idea, and could work if implemented correctly. Though were probably better off without it.

And yes, your new avatar is pretty sweet.

Just say no to QTE.