The reasons for polygamy before it became a social norm are different than the reasons forcing this lax mentality for quick divorces, love-and-leave em scenarios, etc. So for the same reason we say that this generation is different than our grandparents or even our parents, this generation's weird experimentation with less-committed relationships are different than why we were polygamists before. The question is should that matter when choosing a polygamist lifestyle, and I kind of think it does. In those cases it's not a trend back to "natural" behavior, but a lack of discipline that tends to bleed into every aspect of their lives. If a person like you, Muggi, were to compare their lifestyle to say a fickle celebrity on their 3rd marriage in half a decade, that's a disservice to you and pro-polygamists.