Bruce, what a great idea for a discussion!
In my own personal situation, I noticed I was behind the curve in dating because I did straight dating in highschool. I was very adept, (still am) at creating relationships with women, but tentative and inexperienced at creating relationships with other men. If I had been encouraged to date my preference in highschool, I think this would have been different. (Of course I grew up at the dawn of time.)
I definitely think that the discouragement of gay relationships socially plays a role in their dissolution. If you are told by your peers and society that it will never work, it's difficult to believe that it will, and if you don't believe that it will, guess what happens. We are all very capable of making those kinds of fears come true.
The relationship in the article seemed to break up because 'the spark' had gone out of it. It sounded to me, very much like the breakup of a straight relationship. I think people today have unrealistic expectations of what a relationship is supposed to be. It doesn't stay the same over time. There are periods of excitement and boredom. The thing that surprised me was that my partner started out as a sexually exciting stranger and over time became a confidant, a protector, a part of my family that I had chosen, that was closer than any relative I had ever had.
I don't think many people, gay or straight, are taught that establishing a long term relationship means that you are essentially planning a loooooong journey with another person. It's more of a case of: "I think you're hot and you're good in bed, lets move in together." If you were planning a long trip, you'd be pretty picky about who you were going to be stuck with all that time. You'd want to talk over in great detail where you wanted to go and how you wanted to get there. If while you were taking the trip you changed your mind and wanted to go somewhere else or take some detours, you'd need to have someone you could discuss making those kind of changes with. If you'd taken any trips before, you'd know that there will be times when the journey will be tiring and the trip will get boring and tempers will flare, but that won't last forever. If you and your partner don't both want and see the value in a long term relationship, don't be surprised if it doesn't happen.
The group I run around with have all had relationships lasting decades. Relationships that terminated because of death. (None by murder!) The two guys I consider the luckiest are pushing thirty-five years this year. But I will tell you the only way it happened for me was when I got fed up enough and strong enough to tell all the people that were telling me it couldn't happen to go to hell and went for it.