The reason why this, racism, sexism etc are prevalent is because they have historically been big issues and, although they are improving, there is still a lot of prejudice regarding issues like these that needs eradicating. That can only be done by informing people, and to do that you have to make them aware of it. Hopefully there will come a time when such things will no longer be necessary as sexuality etc will no longer be an issue. But we aren't there yet and in order to get there we're going to have to have the issues kept prominently in the public eye and for some it may seem a bit like overkill.
The main issue I had with your original post was the use of the word 'choice' regarding their sexuality. It's not a choice. It's just who people are. Do you remember the day you decided to be attracted to the opposite sex? Or did you just suddenly feel something for someone one day? That's how it worked for me - 8 years old and a girl moved into a house just down the road. I saw her as she got out of the car and I got butterflies, my breathing and pulse quickened and I couldn't take my eyes off her. I didn't decide to do that or have any control over it- it just happened. For other people that just happens with people of the same gender. Meanwhile, I see blokes and I can find them handsome or admire their physique, but I never have a desire to be intimate with them. Again, that isn't a choice it just doesn't happen.
I've tried to justify your terminology and the only way I can come close to being able to do so is if you're ignoring sexuality and just talking about sex. I'm sure many people on here have chosen to have sex with someone who they weren't overly enamoured with. Some people will experiment to try and discover who they are or whatever, but IMO that's a completely different issue and the rainbow laces / LGBTQ+ is about a far deeper meaning and being able to be the person you truly are.