Canadian gun nuts can be found to complain about Canada's "onerous gun laws", even though gun ownership here is proportional by population to gun ownership in the US. A lot of Canadians, make that most Canadians, watch American TV and are more familiar with American laws than with their own, never the less it is still very easy to get a hunting weapon, and as can be seen in the Dawson College shooting they can legally get handguns and semi-autos too. Still Canadians don't generally resort to guns to sort out their problems, or their neighbours or even their wives. Canadians to the greatest extent expect the legal process to work, and expect to work things out eventually. Killing people is just not thought of as a response to anything. Now every society has its loonies.
How many people, had they been armed, could have stopped Todd Wittman. Look it up. None, because they needed to be in a helicopter. And that is true in almost every case, people are not trained to act and think like police in pressure ridden situations. And even in the hands of professionals at close range handguns are notoriously difficult to use effectively.
Mark posted a story many months ago about a jewelry store robbery where the clerk pulled a gun on the man trying to rob the store, then a policeman ran in with his gun drawn. I think 8 people were in the store, 40 shots were fired, and only one found its mark in the robber, and I don't think that one was fatal. That's 3 handguns in an enclosed space and only one person wounded after 40 rounds were expended. That's crazy, and that's exactly what a Tazer might have stopped since they've got that cute laser sighting mark that shows where the shot's going to go. Run in and shoot the robber in the back, end of story, cart him off to jail and charge him with reckless endangerment armed robbery and discharging a firearm in a public place, and make the sentences consecutive. He'll be in a walker before he gets out.
So your response is neither sense, nor common nor applicable to the Canadian, or even the American condition. How many University or College students in the US go around armed and well enough trained to get the gunman and not some innocent bystander? Especially when he's shooting at you. Novice hunters come down with "Buck Fever" when they catch sight of a White Tail in the woods and shoot up half of creation as the deer scampers away. Imagine if the deer were shooting at you first, you'd be more of a menace than a help.
I shot my share of deer when I was young, decided I didn't enjoy it and gave it up, though I still went out in the fall because it was a nice walk. However I killed a squirrel that was gnawing on the insulation in the roof of our front porch about a week ago, and was happy it was gone. Good shot too, air rifle, about 9:30 at night, by the light of the street lights illuminating the park across the road. And nobody anywhere in sight. A little over 30 yards which is long for an air rifle, but I've got a good scope. I chucked him on the railway tracks a block away and never looked back.