I (and I believe most Christians) care about many things in the New Testament far more than the teaching on homosexuality, and would love to spend more time concentrating on those issues. Nevertheless, the homosexual lobby has made acceptence of thier particular perversity into the litmus test for social tolerance in America today, and as such have set themselves up in direct conflict with Christian morals. It is an attack that demands a response
In other words, when they shut up, we'll shut up.
You could turn the other cheek ;)
Seriously though... I know many mainline people who are not pro-homosexuality, and they don't let it consume their days. They do good works, they love their fellow man, and they lead not through violence of word, but through joy at being touched by the word.
If I was a homosexual, being yelled at by somebody frothing at the mouth, would not be a good selling point to see the errors of my ways. On the other hand, if I saw a happy, compassionate man, with a family, overcome by love for their fellow man, their family, their savior, their God... that is the person I would listen to if I wanted to change my ways.
The homosexual hating crowd, in my mind, does fall into the trap of hating the sinner, and not just the sin. They are filled with hatred, spewing from the depths of their hearts. It is why they are so unsucessful at affecting real change. But yelling epithats on street corners feels better, than compassionately teaching somebody the errors in their ways, with love and goodness in their hearts.