Janmcn..."It seems to be true that young people have no problem with same-sex marriage like old people do."

You have taken the bait!!!!

If a statement had to be made about what young VS old people have a problem with it would be more accurate to state something like as in the past, MOST, young people like old people have higher traditional values regarding same sex openness of today. The portrayal to the contrary is fueled by Hollywood, the media and now even the POTUS.....that it is OK/accepted/etc.
At best it might rate that in our propensity of the modern day permissiveness.....it is tolerated!!!

btk