Do you think gay is bad, choyochen? That's the opinion which should be most important to you.
And the only way you have a chance in heck of engendering any change in their opinion - should that be an idea in your head - is if you're own answer is "no, absolutely not".
Here's my opinion: it makes no more sense to apply a judgment of goodness or badness to being gay than it does to being black, white, male, female, tall, short, talented, untalented, young, old, famous or unknown. Judge people on their actions, my friend, not the way they were born.
And if it helps, remember that many such comments come out of ignorance. The truth is there for you to claim it for yourself if you're ready.