Tragic.
As a parent of 2 kids (boy and girl), I've naturally thought about what would happen if one of them turns out to be gay, bi, trans, etc. "Society" tells me that I should feel better about it if it were my daughter being one of those things, but I should be more upset if it were my boy.
I simply don't feel that way. My girl is better at basketball than my boy. If she turns out to be some lesbian athlete (not a stereotype; based on my actual situation), great. I love basketball, and would love to coach her. If my boy turns out to like other boys and wants to wear a dress, then I'll help him pick out a nice prom dress.
Would I be sorrowful about "missing out" on the things that "normal" boys/girls do when they are straight? I guess. But, I'd be looking forward to the other things that they WILL be doing. It's kind of like trading in a car. Do you miss the old car (the comfy seats, the big engine, etc.)? Sure! But, you love things about the new car just as much.
I wouldn't love anyone any less. I wouldn't feel any cumulative loss. And, most importantly, I would support him/her.
In fact, they'd probably be disappointed when they told me by how little of a deal I'd make it. So often, you hear about the "coming out" being some big event in a family. And, not taking anything away from the huge realization that it is for that person, it really is. But, my reaction would be something to the effect of, "Great. I'm so glad you felt comfortable enough to tell us. I love you. Now, let's go out for pizza to celebrate!"
Ultimately, is it worth possibly losing your child? Not even close. Not even in the same ballpark. I'd be FAR more disappointed in my kids if they decided to not go to college than if they became LGBT. As in, light years more!
I just don't get the big deal.