Hmm I suppose you have a point... I'm actually more worried about Poly taking over and becoming the mainstream instead of monogamy. And before you know it the whole definition of romantic love will be changed and will be be just like platonic love.
Hello, first and foremost. This is my first post on this site.
I know you are worried about poly relationships taking over and ruining 'romance'. May I ask you a personal question? How many people have you dated? Were you in love with any of them, or did you date them simply because? I'd be rather surprised, but are you currently married and completely still in love with your very first girlfriend?
The clinical, sterile, rather non-dramatic view of romance has always struck me as silly. We love people, we follow them and proclaim our love, and eventually we move on when something just 'isn't quite right'. I have done it, and I see it still going on among the population. No one immediately finds that 'one and only soul-mate', and immediately all other women (or men, or both) do not exist.
Here is another question. If you are not married to your first girlfriend (and completely monogamous with her, as in you would never view another female/male as more attractive/better in some way than her/him), then do you ever feel yourself mourning a past relationship? Perhaps still in love with that person, despite being in a current relationship? Perhaps missing their smile, or their views, or the way they could make you laugh on a bad day, or even missing some of their faults?
What I'm trying to point out: There is no such thing as a completely monogamous relationship right out of childhood. You have loved others, and fallen out of love with them, and will continue to do so until the day you die. The media and mainstream society sees romantic love in a light that does not exist, but is constantly hoped for by people who fear being seen in a different light. Those that fear condemnation simply tell themselves that 'those thoughts are unclean, I need to be completely faithful even though, in reality, I am pretty miserable'.
Another thing we are told: You cannot be miserable if you are completely and totally in love with someone. That's not true! It's a constant struggle of equality, trust, honesty, communication, and compromise (when appropriate). There are ups and downs, people fall in and out of love, and no relationship is a 'perfect nuclear family'.
I may have went off on a tangent, but I hope you caught my meaning. Fear breeds hate and violence; be above that and, if something you read/see/hear sounds strange to you, research it honestly, with an open mind. It's a very, very big world out there.