Aside from the newly initiated participants, I don't know of any regular SHOOTERS who have only one gun. However, I know of quite a few non-shooters who have only one gun.
As posters on a gun forum, most of us forget that gun ownership and gun enjoyment are not always synonymous. Some people own just one gun, and keep it for personal protection (or other reasons). Some of those folks don't even really like guns, but keep them for the same reasons that they keep changing the batteries in their smoke detectors. However, those of us who would take the time to post on a gun forum are often the types of folks who enjoy shooting, hunting, competing and such, and we often own more than one gun.