For the point of view of the people this article is writing about, that's probably not a very convincing argument. While the statistics you cite are true, they don't take individual circumstances into account. How many of those accidents and thefts were caused by those gun owners being negligent fools? Probably a fair number of them. How much can proper storage, handling, and training mitigate those risks? Probably a lot.
Rather than just just comparing the upside to the downside statistically, you have to compare the upside to the downside for yourself as an individual, including the steps you can take to maximize the former and minimize the latter.
Lumping all gun owners into a statistic is pretty damn useless when you consider "gun owner" ranges from "DEVGRU" to "thinks holding a handgun sideways reduces recoil."
Rather than just just comparing the upside to the downside statistically, you have to compare the upside to the downside for yourself as an individual, including the steps you can take to maximize the former and minimize the latter.