Gun control in Canada - why does anyone really need guns?

As Canada reels after yet another fatal shooting incident, and new Ontario premier Doug Ford comes out in opposition to a handgun ban ("There's lots of legal, responsible handgun owners"), it occurred to me to research to what extent guns are actually used in self-defence in practice. After all, self-defence is the most common justification for owning a gun and, as Toronto Mayor John Tory said after Toronto's latest shooting: "Why does anyone in this city need to have a gun at all?"
This seems like a reasonable question, but it turns out that, even in America where gun crime (and the ongoing debate over gun control) is rampant, this is a surprisingly difficult question to answer, and a surprisingly difficult thing to measure. There is much controversy over those few studies that have been carried out, not least because the concept of self-defence itself is a loaded and subjective one. The non-partisan RAND Corporation's analysis of the available research concludes that more research is needed (and, in particular, that the NRA-sponsored ban on using federal funds to research it should be revoked).
Gun advocate Gary Kleck's survey of 5,000 Americans yielded the conclusion that 66 of them had used their guns in self-defence in some way in the last year, i.e. about 1.3%. Kleck then extrapolated this over the adult population of the country to arrive at a figure of 2.5 million, a figure that has been widely disseminated by the gun lobby and even used by the US Supreme Court. However, gun control advocates have argued that the survey was phrased in a leading manner, and that the data was misinterpreted anyway. Even Kleck agrees that victims of crime are better off calling the police than whipping out a firearm.
A different analysis by Harvard's David Hemenway concludes that victims use guns in less than 1% of contact crimes, that claims that millions of people use guns to protect themselves each year are invalid, and that guns are actually more likely to be used to escalate arguments and for intimidation (particularly of family members) than in self-defence. One way of looking at it is that, for every gun used in self-defence, six more are used to commit a crime. Hemenway further concludes that victims using guns are no less likely to be injured than those who employ other means of protective action, and indeed that most of the claims made for the benefits of gun ownership are in fact myths.
The Violence Policy Centre published an analysis in 2012 which enumerated just 259 instances where a violent crime had been thwarted by a gun used in self-defence during that year. This is in a country which owns about 300 million guns, and in which there are annually about 1.2 million violent crimes (i.e. opportunities in which self-defence could be employed).
So, although the data in Canada on the issue appears to be non-existent, and data in America is at best questionable, the weight of what evidence is available indicates that guns are probably not much use as self-defence. As with so many important moral questions, there are no easy conclusions. So, why don't we leave the decision up to the survivors, and the relatives of the victims, of the recent shootings in Toronto and Fredericton?