Maybe it also has to do with the "disposable society" - relationships are disposable, like everything else.

I recall the consternation amongst my extended family as a child when my aunt became engaged to a divorcee - the serious visits to the (sympathetic) minister, the breaking down of the "you can't get married in the church if you're divorced" taboo.

Now, no one turns a hair. Those of us in long term marriages are the minority.