If the governments would do their basic job, the vast majority of law-abiding citizens would not need guns for self-defense. But our current governments are sadly unwilling to do their basic job.
Except that stand-your-ground laws and easy concealed-carry look to make things worse:
Also, the pages talk about "homicide", but that term, at least as it's usually used in such general studies, includes justified self-defense homicides. So if total homicides do in fact go up as a result of these laws, that could be because criminals who would have gotten away with their crimes before the laws were passed were instead killed by their intended victims in self defense. That's not a problem, it's exactly what the laws are for.
If the government not only is not willing to do its duty to enforce the laws against crime, but even has the gall to claim that that's not the government's job, then all the more reason why law-abiding citizens will be motivated to exercise their right to keep and bear arms.