I don't think it's a matter of being "narrow-mindedly focused on this particular sin", because most Christians are just as concerned over other sins. It's just that the media tends to focus on homosexuality as a "prying concern" of the "Christian Right". Which is unfair because most Christians I know are more upset about the fact that 1.5 million babies are killed each year by abortion.
I agree about the abortion, but most pulpits that I've heard speak out against homosexual attraction don't say nearly as much about - say - adultery or fornication.
Your mileage may vary.
Shalom.