See, if I were to use that gun, I'd have to be wise and use it on people whose fame removal would create a domino effect that would lead to many more celebrities losing their fame and popularity.
For example, if I were sick of the winners of American Idol, I wouldn't try to shoot them individually. I'd try to get the person responsible for these people becoming successful in the first place. I'd have to shoot Simon Cowell, who helped make the show popular in this country in the first place. With him gone, American Idol would tank and there won't be any more overhyped Idols from now on.
If I got sick of MTV and all the rappers/punks/whores that are promoted and become instantly popular, I'd have to hit the person responsible for MTV's success, and all these "artists" would no longer have a place to promote their "music".