You sir are talking noonsense. What you are saying is that you, unlike all the other cowards, would have jumped in there unarmed, and fought the maniac with the knife to save the others. I doubt that very much. Heroism in hindsight, after the fact, is pretty easy to come by. There were three guys who did their best to keep the armed maniac on the bus. These guys were heros of sorts bur probably not as good as Cannuck who would have flown in and saved everyone if he could have found his cape.
I would have, I bet a few others would have too. The difference is I was raised that way, I know most people aren't. They are raised that they are a unique and special snowflake and its the job of "other people" to do the right thing.
As pointed out, in countries where they aren't trained to be cowards in school, they do act. A man opened fire WITH A GUN in a us church and people swarmed him.
This is one guy, with a knife, bent over in an awkward position, while people are bumping by him, shoulder to shoulder, to get off the bus. Any one of those people could have stopped him, add in the scores more and they could have easily held him down and disarmed him.
Its the same reason why if there is a crash scene you have to point at one specific person and say "You go get help", otherwise no one will.