The divorce rates in the States aren't as high as common discourse makes it seem. It's not half of all marriages.
The problem with marriage is the happiest day of the marriage is the first day and it only goes downhill from there. And, once kids are added happiness dramatically plummets. (Depressing info learned from a uni class on family.)
And, shit if there is a significant difference in marriage rate success by country, I'd imagine it comes back to many of the issues people in the US face that others don't. Healthcare costs, day-care costs, housing costs (Canada def has this problem too), student loans, overworked, underpaid, work comes first mentality, lack integration among family generations, lack of support mental health, addictions, etc.
But, that being said, I'm not necessarily sure divorce should be stigmatized. I mean why promote being stuck in a shitty relationship?
Hell, I think we should have a tax break for people the year they get divorced, because, fuck, divorce is expensive. And, the court costs are absurd. Why the fuck can someone get a marriage certificate for 40 bucks but it costs 400 to file for divorce?