I'm grateful it was just knives - there's no "collateral damage". If this was in the USA, bystanders would have been hit by stray bullets. And if the perp had a semi-auto, it's much worse...
Interesting though - China essentially banned knives in Xinjiang when a company I was connected to worked in that province - to 'keep people safe' from Uyghur 'terrorists' (the region our manager lived was mostly farmers). Each knife had a serial number engraved on it, and restaurants that were allowed to have knives had to chain them to the tables. It's crazy. They also have CCTV's at literally every street corner, with facial recognition and tracking. And more police per capita than Soviet-era East Berlin, all with quotas to arrest x # of Uyghers per week.
Safety and freedom is a balance, and we often get it wrong - both sides can end in harm. But no one needs a semi auto. If you're fighting a corrupt government as a militia, their military will just bomb the tar out of you (a la Russia in Chechnya). And no hunter or sport shooter needs anything more than a rifle (though I'm more of an archery guy). Statistics show that citizens with guns result in more innocent bystander deaths consistently across the decades (far outweighing the 2 or 3 stories we hear about 'a good guy with a gun')
Anyway, I think with problems like these, one solution is never enough - have to treat as many contributing factors as possible. Psychological, social/community elements, economical, legislative, etc. If we pretend like one thing will solve everything (like "fire Maurice"), we will fail. Some solutions are easy and have a big instant impact and should be implemented, and banning Assault rifles is certainly one (firing Maurice sooner would have helped the Jets, too - just was never the *whole* solution).
I think part of the problem may be that you're not really as certain of your terminology as you think you are. An AR-15, the symbol for the anti-gun lobby is a semi-automatic rifle. But a Browning Mark III is also a semi-automatic rifle that if you saw a picture of you wouldn't bat an eye at. It looks just like a comparable bolt action rifle minus the bolt and doesn't have a scary magazine that an action hero would slap in place.
A semi-automatic weapon is simply a weapon that can automatically load the next cartridge into the chamber to be fired again by pulling the trigger again (this may be a rifle, shotgun or pistol). Does that increase the ability to fire more rapidly? Yes, to an extent it certainly does. But my suspicion, based on the description you provided, is you are thinking of an automatic weapon. An automatic weapon can fire repeatedly simply by holding down the trigger, resulting in the spray type pattern you are imagining occurring in a violent shootout or military type situation. The media and politicians alike are very poorly versed in terminology for firearms and in general get it wrong more than they get it right. Magazine capacities can certainly contribute to the issues, which is the biggest issue with an AR-15. If an AR-15 had a reduced capacity magazine it would be roughly as scary as any other semi-automatic rifle of similar capacity. Many media and politicians assume the "AR" stands for automatic rifle, which it is not, it is short for ArmaLite Rifle.
Rifles may be single shot (bolt/lever action) or may be semi-automatic as well, meaning the next round is chambered by the mechanism in place and ready to fire by pulling the trigger again. I think your statement on whether hunters need a semi-automatic weapon is subjective - there are many factors that go into making an accurate shot - wind, distance, caliber, etc. This means that not every single shot, no matter how good you think someone should be, is a kill shot. Being able to fire a second shot more rapidly may result in the faster killing on an already wounded animal that may otherwise escape or move out of range and subsequently die a lingering, painful death. As for sport shooters you are welcome to your opinion, but nobody really needs a car that goes faster than 60 kmh, so maybe we should ban anything that does, perhaps starting with the electric cars that have vastly improved and entirely unnecessary acceleration? Agree? Yes, that's hyperbole, but be careful how you impose your views lest others impose their views on yours. Let me put it another way: why does anyone need anything but a simple recurve bow? Shouldn't we ban compound bows and crossbows? I mean really, if you're just shooting targets, why does fps matter?
Canada, to this point, has reached a reasonable position on firearms ownership. The restrictions and rules in place are substantial. That said, none of them prevent exactly the type of crimes you are worried about. Take a look at Toronto and find out what weapons are being used and how many bystanders are shot in just the type of situation you're worried about (hell, look at the gun crime rate in Chicago, the city with the strongest gun control regulations in the U.S.). But the locks, transport rules, more severe rules on restricted firearms and a general lack of gun culture has Canada in a far better place than the U.S. What is baffling is the current reductions in gun penalties for offenders while placing further restrictions on law abiding gun owners.
Not trying to make this political, but let's get terminology correct.