It's a defect because you think it's a defect. And it's wrong because you think it's wrong. Other than that, any argument you put forth can be easily invalidated.
I didn't say it was a defect. But it's either a defect or a choice. If it's a defect? Find a cure. If it's a choice then that choice doesn't deserve to be legitimized as normal any more than sex with goats, fucking a carnival ride, raping palm trees or having a dozen cousin wives would.
I don't care what grown people do in private. Where I have a problem is forcing public acceptance of a perversion of nature. I don't my kids to be taught by teachers held up as role models who openly endorse their gay lifestyle. I don't want them to see it is a normal or acceptable alternative. Kids are already confused. The surge of hormones during the teenage years makes them crazy already. Without the moral compass that traditional values provide the confusion becomes worse. My kid is already dealing with a number of friends who have decided that since "boys don't like me" they must be a lesbian. Or because they are gawky and ugly at 13 they "maybe should have been a boy". That a such bullshit. These kids need guidance. Not "hey, hey, it's okay! Graft dick down there today!!"
It is a perversion of nature. It goes against the natural order. Therefore it's wrong.
There will be consequences. Look to Rome. We are on the same path.