It is not fashionable, it is just a right that homosexuals have been denied in most societies for a long time, but are finally seeing most of the progressive societies to recognize they have equal rights to all other people. Like all human rights issues it tends to get a lot of media coverage because it is controversial and people enjoy hearing about controversy.These days it seems to be fashionable to marry ppl from the same gender.
Where does the idea come from? What are your bases?
Fortunately for the public we still have lots of bigoted people to keep entertaining them. Fortunately for society as a whole these bigots are the ones that will soon have nowhere to go but to change their thinking or just keep quiet.