One of these processes is the development of the middle class. Why is it so important?
I would agree so far....but I wouldn't bring political correctness into this.
IMHO the matter is much easier....a well off, educated middle class demands rights, individual rights. They don't want to live anylonger as others dictate to them, they have the money, they line the states cases, they bring the jobs, they go around and see other places which give them ideas, they want to live as they see fit, also sexually.
They become so powerful and influential that neither god, nor church nor king nor party head nor old traditions whatsoever can stop them to get what they want, they get greedy. And why shouldn't they!
The bigger the middle class the bigger the liberal rights in one country...that belongs together!
Thing is you don't get economical progress without an equally growing affluent, liberal middle class...to fight LGBT's is useless in that regard.
PS: It will be interesting to see the same principle working in China. There too a rising middle class is demanding it's rights, the fight with the all-ruling communist party is already on.
PPS: It works the other way around too...a shrinking middle class opens the door again for illiberal opinions...nicely to see in East Germany after the de-industrialization after the "Wende" and the impoverished parts (Rust belt) of the US.