I think it's appalling to do this in the name of religion or any other reason. Do they think homosexuals are pretending to be gay to piss 'God' off? If there is a God- who do you suppose created homosexuality in the first place? And why? To see if they would resist their urges? I mean- maybe. A lot of religion does seem set up like that. Resist lust, gluttony, wrath etc. to prove how much you love God. Fine- if you want to play along. Who knows? Maybe it's all true and you'll get your reward in heaven. But, a lot of the world is secular now. Religion isn't law. All of us shouldn't have to abide by someone else's beliefs.
Even when it was illegal, it messed up people's lives. Imagine being told you couldn't consentually love someone who loved you back. That's so messed up!
As for people saying it isn't 'natural'. Neither is wearing clothes, driving a car, eating processed food, using the internet, watching Netflix etc. You wanna give those things up too? Besides- we do see homosexuality in animals sometimes.
The other argument I guess is promiscuity and the spread of STDs. I know straight people who are incredibly promiscuous as well. Honestly- it's not my thing but, whatever their sexuality- they both know the risks and how to protect themselves from it. It's up to them. I believe that anything that is consensual and not hurting others (I'm not keen on people who cheat,) that's their business and no one elses.
There's also the more Catholic belief that sex should be in the service of creating children... Like we need more humans on this overstretched planet!
I've even heard the argument that AIDS was God's punishment for gays... So, I'll leave it with the wonderfully outspoken Ricky Gervais on God giving the virus AIDS it's mission...