Because these countries are cherrypicked. If your list included places like Mexico, Brazil, Finland and Switzerland you would have a very different idea of the relation between gun ownership and gun homicide rates.
Also, I personally do not care one whit about gun homicide rates. I care about overall homicide rates, and I think most everyone else does too.
Also, I personally do not care one whit about gun homicide rates. I care about overall homicide rates, and I think most everyone else does too.