Why is it bad that I don't want my son to be gay?edit

I saw one comment, the lady said she was downvoted a lot when she said she doesn't want her son to be gay. Why is it bad? I don't want my kids to be gay as well. I'm not Christian and don't think that it's a sin or something. I just prefer traditional family, why is it bad?

EDIT: thanks for replies. I would accept and still love my child of course. But as some of you said as well - nobody really hopes that their child will be gay, then why is that a bad thing? I wish that my child is going to be straight, why is that a bad thing?