I think fezzy has it about right. These days, people are looking for that "perfect" person that embodies their greatest fantasies, and when he cannot find that person, they move on. It is far different that generations before us.
I would much prefer a monogamous relationship myself, because I do value building a relationship with someone who knows, understands and values me and vice versa, and all the intimate stuff that goes along with that is far better than casual things, but I understand the other viewpoint and often wonder if we can truly be monogamous anymore, and whether putting the time into a relationship only when it will fail is worth it.
Yes. Preferably strict, lifelong monogamy, removing only the morally irrelevant variable of gender.
Why should people feel compelled to remain in a relationship that is making them miserable until the day one partner drops dead? People don't just separate/divorce for the hell of it. Being in a bad relationship is the most stressful, unhealthy thing ever. There's nothing moral about it.
No one should. But people breaking up these days is much higher than in the past, and the reasons are much more self-centered than they once were. People used to work things out, work together and fix problems. Now, they just call their attorney and file for divorce.
Let me be clear: some breakups are warranted. Emotional and physical abuse do play a role, and no one should stay in relationships like that. But I have trouble understanding when a couple just ends a marriage when they hit a rough patch because one partner doesn't make them happy anymore or doesn't have enough money, etc. It's just annoying. Far too often now, people expect perfection out of relationships because of what we see on TV or movies, and when that "love story" fails, they get out.
Girls are the worst when it comes to this. They all want to love a story like The Notebook or whatever, and if that doesn't happen, they grow flaky. Part of the reason my ex and I broke up after 2 and a half years was distance and because her perfect love story was falling apart. She did not want to work on it or try to work through the distance, which was temporary, and instead just wanted to end it.