There's no nicer way to say this but...

[kılıç_mehmet]

So allowing gay marriage is going to be disastrous? Because all these years it's been fine, but if we let them marry, it'll be the end of the world?

Homosexuality has been around as long as arseholes have; it's not going to start undermining society now when it hasn't since the dawn of human civilization. The Greeks and Romans allowed homosexuality, and the modern western world ( even Turkey to an extent - the Sultan did call himself Ceaser [Kayseri] after all ) is built on their foundations.

End of the world, I'd say not. But it certainly would destroy a pillar of society.
As I previously mentioned, Greeks and Romans were notorious pedarasts, and the Ottomans have adopted such ugly practices from the persians who were also notorious pedarasts, wheras it was grave offense in Turkish societies ever since from the Huns.